HK40048925A - Cryptographic asic for key hierarchy enforcement - Google Patents
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Description
This application claims the priority benefit of U.S. Ser. No. 15/975,615, filed on May 9, 2018 , and entitled "CRYPTOGRAPHIC ASIC FOR KEY HIERARCHY ENFORCEMENT," which claims the priority benefit of commonly-assigned provisional application U.S. Ser. No. 62/662,544, filed on April 25, 2018 , and entitled "CRYPTOGRAPHIC ASIC FOR DERIVATIVE KEY Hierarchy".
The disclosed technology relates generally to the design of integrated electronic circuits, and more particularly, some embodiments relate to the design of cryptographic integrated circuits.
Application-specific integrated circuits (ASICs) are integrated circuits designed and built to serve a particular purpose or application. ASICs provide fast computational speed compared with slower, more generalized solutions, such as software solutions running on general-purpose processors or field programmable gate arrays (FPGAs). As the name implies, ASICs are generally designed to perform only one specific application, resulting in a trade-off between flexibility and computational speed. ASICs are increasing in importance in cryptography-related fields, such as proof-of-work systems, digital rights management systems, and other applications generally having stringent speed and efficiency requirements.
In Internet Engineering Task Force, IETF, Internet-Draft entitled "PKCS #5 Password Based Key Derivation Function 2 (PBKDF2) Test Vectors" [draft-josefsson-pbkdf2-testvectors-03.txt], Josefsson S. discloses text vectors for the PKCS #5 Password Based Key Derivation Function 2 (PBKDF2) with the Hash-based Message Authentication Code (HMAC) Secure Hash Algorithm (SHA-1) pseudorandom function.
The invention is a cryptographic integrated circuit and a method as defined in the appended claims.
In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate various embodiments discussed in the present document.
- Figure 1 shows a block diagram of a transform-enabled cryptographic circuit containing a transform enabled hashing core, implemented as a stand-alone integrated circuit.
- Figure 2 shows a block diagram of the transform-enabled hashing core.
- Figure 3 shows a block diagram of an information hierarchy.
- Figure 4 shows a flowchart of the management methodology using the information hierarchy.
- Figure 5 shows a functional diagram of an internally-programming integrated circuit, according to an embodiment.
- Figure 6 shows a flowchart of a customized equipment programming process for information stream management, according to an embodiment.
- Figure 7 shows a conventional autonomous product with little or no internal communications security.
- Figure 8 shows an autonomous product with secure inter-chip communications.
- Figure 9 shows the autonomous product processor in further detail.
- Figure 10 shows an integrated circuit with secure inter-chip communications and non-volatile memory.
- Figure 11 shows a flowchart of a secure inter-chip communications methodology.
- Figure 12 shows a flowchart of a methodology for calculating a cryptographically secure and verifiable unique processor identifier.
- Figure 13 shows a flowchart of a methodology for verifying the transform integrity of a cryptographic integrated circuit.
- Figure 14 shows a computing component that may carry out the functionality described herein.
Embodiments of the technology disclosed herein are directed toward the design, fabrication, programming, and utilization of application specific integrated circuits for cryptography-related applications. More particularly, various embodiments of the technology disclosed herein relate to ASICs having one or several programmable transformation functions embodied as circuitry incorporated into the integrated circuit's high speed datapath. By encoding transformation function as datapath circuitry, embodiments of the technology disclosed herein enable ASICs to implement any one of a very broad range of proof-of-work calculations, as selected by the user. The proof-of-work based cryptographic verification processes include the cryptographic network transaction verification systems often used in the emerging field of blockchain technology.
Unless indicated otherwise, the examples in this and following paragraphs are not embodiments of the invention but are presented for illustration purposes only. In an example, a cryptographic integrated circuit for managing operations on an information stream includes a first one-way function (OWF) circuit block that generates a hash of an input message, a programmable transformation function circuit block that is customized by a transform key and transforms the hash into a transformed hash, and a second OWF circuit block that generates a second hash of the transformed hash as an output result. The cryptographic integrated circuit controls an information stream knowledge hierarchy by performing operations enabling a user to identify the information stream, process an input message from the information stream, or create the information stream.
In another example, a cryptographic method for managing operations on an information stream includes processing an input message from the information stream by hashing the input message, performing a customized transforming of the hash, and hashing the transformed hash into an output result, with the transforming customized based on a transform key, and enabling creating the information stream based on a user passphrase from which the transform key is derived.
In another example, a non-transitory computer-readable storage medium contains instructions which, when executed by a processor, cause a computer to execute cryptographic operations for managing operations on an information stream. The operations include processing an input message from the information stream by hashing the input message, performing a customized transforming of the hash, and hashing the transformed hash into an output result, with the transforming customized based on a transform key, and enabling creating the information stream based on a user passphrase from which the transform key is derived.
In an example, a cryptographic integrated circuit for managing operations on an information stream includes a transform key generator that derives a transform key from a temporary copy of a user passphrase, and a one-time programmable (OTP) memory that stores the transform key in isolation using programming pulses from external circuitry. The circuit further includes a first one-way function (OWF) circuit block that generates a hash of an input message, a programmable transformation function circuit block that is customized by a transform key and transforms the hash into a transformed hash, and a second OWF circuit block that generates a second hash of the transformed hash as an output result, wherein the operations include identifying the information stream, processing an input message from the information stream into the output result, and/or creating the information stream.
In another example, a cryptographic method for managing operations on an information stream includes deriving a transform key from a temporary copy of a user passphrase, and storing the transform key in a one-time programmable memory in isolation using programming pulses from external circuitry. The method further includes processing an input message from the information stream by hashing the input message, performing a customized transforming of the hash, and hashing the transformed hash into an output result, with the transforming customized based on a transform key, and enabling creating the information stream based on a user passphrase from which the transform key is derived.
In another example, a system for managing operations on an information stream includes means for deriving a transform key from a temporary copy of a user passphrase, and means for storing the transform key in a one-time programmable memory in isolation using programming pulses from external circuitry. The system further includes means for processing an input message from the information stream by hashing the input message, performing a customized transforming of the hash, and hashing the transformed hash into an output result, with the transforming customized based on a transform key, and means for enabling creating the information stream based on a user passphrase from which the transform key is derived.
In an example, a cryptographic integrated circuit for managing operations on an information stream includes a transform key generator that derives a transform key from a temporary copy of a user passphrase, and a one-time programmable memory that stores the transform key in isolation using programming pulses from internal circuitry. The circuit further includes a first one-way function (OWF) circuit block that generates a hash of an input message, a programmable transformation function circuit block that is customized by a transform key and transforms the hash into a transformed hash, and a second OWF circuit block that generates a second hash of the transformed hash as an output result, wherein the operations include identifying the information stream, processing an input message from the information stream into the output result, and/or creating the information stream.
In another example, a cryptographic method for managing operations on an information stream includes deriving a transform key from a temporary copy of a user passphrase, and storing the transform key in a one-time programmable memory in isolation using programming pulses from internal circuitry. The method further includes processing an input message from the information stream by hashing the input message, performing a customized transforming of the hash, and hashing the transformed hash into an output result, with the transforming customized based on a transform key, and enabling creating the information stream based on a user passphrase from which the transform key is derived.
In another example, a system for managing operations on an information stream includes means for deriving a transform key from a temporary copy of a user passphrase, and means for storing the transform key in a one-time programmable memory in isolation using programming pulses from internal circuitry. The system further includes means for processing an input message from the information stream by hashing the input message, performing a customized transforming of the hash, and hashing the transformed hash into an output result, with the transforming customized based on a transform key, and means for enabling creating the information stream based on a user passphrase from which the transform key is derived.
In an example, an integrated circuit for autonomously storing context data includes a one-time programmable memory circuit block programmed by internal programming circuitry to store the context data in isolation, and a secure communications circuit block to control retrieval of the context data.
In another example, a cryptographic method for autonomously storing context data in an integrated circuit includes storing the context data in isolation in a one-time programmable memory circuit block programmed by internal programming circuitry, and controlling retrieval of the context data with a secure communications circuit block.
In another example, a system for autonomously storing context data includes means for storing the context data in isolation in a one-time programmable memory circuit block programmed by internal programming circuitry, and means for controlling retrieval of the context data with a secure communications circuit block.
In an example, a cryptographic integrated circuit for managing operations on an information stream includes a one-time programmable memory configured to store in isolation a unique configuration key defined by a foundry for each instance of the integrated circuit, and a transformed hash generator configured to derive a unique circuit identifier for each instance of the integrated circuit from an interrogation message using the configuration key.
In another example, a cryptographic method for managing operations on an information stream includes storing in isolation in a one-time programmable memory in an integrated circuit a unique configuration key defined by a foundry for each instance of the integrated circuit, and deriving a unique circuit identifier for each instance of the integrated circuit from an interrogation message using the configuration key.
In another example, a system for managing operations on an information stream includes means for storing in isolation in a one-time programmable memory circuit block a unique configuration key defined by a foundry for each instance of an integrated circuit, and means for deriving a unique circuit identifier for each instance of the integrated circuit from an interrogation message using the configuration key.
In an example, a cryptographic integrated circuit for verifying circuit validity for managing operations on an information stream includes a one-time programmable memory configured to store in isolation a unique internal identifier value defined by one of a foundry and a user, for each instance of the integrated circuit, a transformed hash generator configured to calculate the internal identifier value for each instance of the integrated circuit from a predetermined input message, and a comparator that determines circuit validity by matching the stored internal identifier value with the calculated internal identifier value.
In another example, a cryptographic method for verifying circuit validity for managing operations on an information stream includes storing in isolation in a one-time programmable memory in an integrated circuit a unique internal identifier value defined by one of a foundry and a user, for each instance of an integrated circuit, calculating the internal identifier value for each for each instance of the integrated circuit from a predetermined input message, and determining circuit validity by matching the stored internal identifier value with the calculated internal identifier value.
In another example, a system for verifying circuit validity for managing operations on an information stream includes means for storing in isolation in a one-time programmable memory in an integrated circuit a unique internal identifier value defined by one of a foundry and a user, for each instance of an integrated circuit, means for calculating the internal identifier value for each for each instance of the integrated circuit from a predetermined input message, and means for determining circuit validity by matching the stored internal identifier value with the calculated internal identifier value.
The transform-enabled cryptographic circuit 100 includes an integrated circuit 102 containing a programming and configuration interface 104, a transform-enabled hashing core 106, and a configuration key 108. Configuration key 108 comprises a string of binary digits, and may also be referred to as a transform key or transformation key. In some embodiments, a transform key is derived from the configuration key 108.
Two users 110 and 112 may access the integrated circuit 102, with a first user 110 accessing the programming and configuration interface 104, and a second user 112 accessing the transform-enabled hashing core 106. The second user 112 uses a hashing core user interface (not shown). In various embodiments, some or all of the functions of the configuration and programming interface 104 and the hashing core user interface are combined into a single configuration, programming, and hashing core user interface, while in other embodiments such functions are divided among more than two interfaces.
The general mode of operation is that the first user 110 uses the programming and configuration interface 104 to both configure various parameters of the operation of the integrated circuit 102 and to program one or more configuration keys 108 into the programmable transformation function or functions in the transform-enabled hashing core 106, where they are implemented as datapath circuitry. Note that configuration keys 108 are not conventional cryptographic keys in the strictest sense, but instead are customized descriptions of how a selected transformation function is to be activated, such as to transform original input data into transformed input data.
The second user 112 simply enters an input value or transaction or message that is directly communicated to the transform-enabled hashing core 106 that will calculate and output the corresponding hash value. For a given input message and configuration key 104, any user of an instance of transform-enabled cryptographic circuit 100 should be able to calculate the same corresponding hash value. The input message comprises a transaction block header from a blockchain , which is subjected to further operations. Note that processing the input message to produce a corresponding hash value is carried out by the second user without requiring knowledge of the configuration key or keys programmed into the programmable transform-enabled hashing core 106.
Due to the interaction thus established between the programmatic transformation and certain mathematical properties of the cryptographic algorithms involved (particularly, as noted earlier, their nature as OWFs that are easy to perform but hard to revert), the combined effect is to produce a systemic transformation of the bits contained in the final value calculated by the circuit. The transformation is not easily deciphered, not easily distinguishable from noise, and not easily replicable by a party lacking full prior knowledge of the key or keys programmed into the transformation function. Yet the transformation is fully consistent and easily replicable, and thus verifiable, by a party with prior knowledge of the keys or access to the means to utilize them in calculation even while lacking knowledge of them (including a party in possession of a previously-programmed ASIC that embodies said keys within its datapath circuitry).
In some embodiments, each user is a person, while in other embodiments each user is an automated process such as wallet software, mining software or other kinds of automated processes. In certain embodiments the second user 112 also has access to the configuration of the various operating aspects of the integrated circuit 102 as described above. In certain embodiments there is a single interface for the configuration of the various operating aspects of the integrated circuit 102 as a whole, with the programming of keys and the obtaining of final transform-enabled hash values calculated on the basis of data supplied by a user. In other embodiments some or all of those functions are separate. In certain embodiments, the integrated circuit 102 is part of a larger computing system, such as a mining system, a hardware wallet, a secure token or dongle, or others. In some embodiments, various implementations of the integrated circuit 102 are part of a system incorporating one or more of such integrated circuits containing other implementations of the technology described herein.
In some embodiments, various implementations of the integrated circuit 102 are physically integrated into the same semiconductor material, such as silicon, as other embodiments of the technology described herein. In some such embodiments, the integrated circuit 102 are further connected to other embodiments of the technology described herein. The integrated circuit 102 has a shared access to programmable transformation function or functions in the transform-enabled hashing core 106 as other circuits within the same integrated circuit 102. In various other embodiments, the transform-enabled cryptographic circuit 100 is physically integrated into the same semiconductor material as another integrated circuit carrying out a different task, such as a microprocessor, a network processor, a system-on-a-chip, and others. In certain embodiments, the transform-enabled hashing core 106 embodies the configuration key 108 as circuitry by means of one-time programmable circuit elements such as micro-fuses, while in certain embodiments re-writeable circuit elements, such as non-volatile random access memory (RAM) are used, and in other embodiments other methods are used.
In general, a hashing block is configured as a set of circuitry that executes the mathematical operations defined by the applicable hashing algorithm. One widely used hashing algorithm is the Secure Hashing Algorithm (SHA), the second version of which is now used as a standard hashing algorithm, often for input messages of 256 bits in length (referred to herein as SHA-256). However, this disclosure is not limited in that regard, as any OWF may be used.
The output of the first hashing block 204 is a hash 206 of the input message 202. A hash, sometimes known as a message digest, is used as a type of cryptographic description of original message content. Hashes are convenient for various cryptographic purposes as they may be easily computed from an input message, but are computationally difficult to invert for determination of the original input message. Hashing algorithms are sometimes referred to as trapdoor functions for this reason.
The hash 206 is then processed by an adjustable or customizably programmable transformation function 208, which is implemented in circuitry as a transform block. Once programmed, the circuitry within the transform block effects a specific programmatic transformation upon the data provided to it, reflecting the configuration key 108 provided to it. Thus, and regardless of the content of the data received by the transform block, the transformation the circuitry applies will directly and consistently affect the final value calculated by circuitry further along the datapath.
The programmable transformation function 208 generates a transformed hash 210 of the input message 202. The transformation function is very simple, such as an inversion of bits in one embodiment, or the transposition or swapping of bits in another embodiment, or combinations thereof. The programming of a transformation function therefore customizes the treatment to which data fed into the transformation function is subjected. The configuration key 108 controls the specific programming of the programmable transformation function 208. The configuration key 108 is simply a string of binary digits denoting which corresponding bits of input data are to be inverted, transposed, or both, by the programmable transformation function 208, according to various embodiments. That is, in one embodiment each particular bit of the configuration key 108 determines whether each corresponding particular bit of input data is passed through directly without transformation, or is transformed.
The transformed hash 210 of the original input message 202 is then processed by a second OWF implementation or hashing block 212. In some embodiments, the second hashing block 212 implements the same cryptographic operation as the first hashing block 204. In other embodiments, the second hashing block 212 implements a different cryptographic operation than the first hashing block 204.
Each OWF implementation protects the data provided to it, through its non-invertible nature. Conceptually, the input data submitted to an OWF is kept within a cryptographic "shadow" that prevents its discovery from the results of the hashing, through computational infeasibility. A party may thus look "downstream" and see the results of a hash operation that is applied to an input, but cannot feasibly look "upstream" and see the original input provided to the hash operation. The output 214 of the transform-enabled hashing core 106 is thus a hash of a transformed hash of the original input message 202.
Knowledge of the user passphrase 302 and of the calculation process whereby the transform key 306 is calculated based on the user passphrase 302 enables the easy calculation of the transform key 306. However, knowledge of the transform key 306 and of the process by which it is calculated on the basis of the user passphrase 302 does not enable easy calculation of the user passphrase 302. Thus, in such embodiments, knowledge of the user passphrase 302 implies knowledge of the transform key 306, but knowledge of the transform key 306 does not imply knowledge of the user passphrase 302. Knowledge of the user passphrase 302 is required to configure the transformation function 208 and thus the integrated circuit 102 to perform in the specific manner that is described by user passphrase 302.
To summarize, the original input message 202 or transaction is protected by the first OWF 204, transformed by the custom-programmed transformation function 208 per the configuration key 108, and the hashed transformed original input message 210 and the customization of the transform function 208 is effectively protected again by the second OWF 212.
The embodiments described in paragraphs 55-75 and 98-151 are not according to the invention and are present for illustration purposes only. The present inventor has realized, among other things, that secure programming of the transform-enabled cryptographic circuit 100 enables a variety of advantages. A novel information hierarchy is defined and cryptographically secured via a transform-enabled cryptographic circuit 100 that stores configuration data without providing external visibility or accessibility to that data. The information hierarchy enables a cryptographic management methodology that enables the creation of, provides for useful processing of, and allows the simple identification of an information stream to be processed. The information stream comprises a blockchain.
Certain embodiments of the technology disclosed herein allow a user to enable third parties to easily verify the proofs-of-work produced by transform-enabled integrated circuits by providing the third parties with knowledge of the transform key and thus enabling them to verify such proofs of work by means of software running on general-purpose microprocessors, FPGAs programmed for this purpose, or other means. But knowledge of the transform key does not enable the third parties to program additional copies of the integrated circuit to calculate transform-modified proofs-of-work in the same manner as they are calculated by instances of the integrated circuit that have been programmed using the user passphrase. The circuit described has been designed to perform such validations while not revealing information about the precise mathematical operations involved in the production of the transformed hash values verified.
Further, the system described is also applicable to fields other than the field of blockchain technology. In such other fields, the system is used for the creation of other secure hardware-based products.
The user passphrase 302 comprises a string of binary numbers, or a string of text that may be more easily remembered by a human user but still readily converted into a string of binary numbers. The secrecy of the user passphrase 302 prevents any other parties from enabling the creation of the information stream being managed. The user passphrase 302 also enables control of all other operations performed in the information hierarchy 300, e.g., processing of the information stream, and identification of the information stream.
The transform-enabled cryptographic circuit 100 receives the user passphrase 302 and performs on-chip transform key generation processing 304 to produce a transform key 306. In one embodiment, the transform key 306 is the same as configuration key 108, although embodiments in which the transform key 306 is derived from the configuration key 108 are also encompassed by this disclosure. The on-chip transform key generation 304 processing, rather than a separate off-chip implementation, enhances security, as will be described.
The transform key generation 304 processing comprises at least one application of an OWF to the user passphrase 302. In one embodiment, the transform key generation 304 processing comprises two sequential applications of a one way function to the user passphrase 302. The transform key generation 304 processing comprises two sequential applications of SHA-256 to the user passphrase 302, although this disclosure is not limited in that regard.
Use of an OWF renders derivation of the user passphrase 302 from the transform key 306 computationally infeasible. That is, the user passphrase 302 is upstream of the OWF and is therefore cryptographically secure. Figure 3 thus denotes the transform key 306 as proceeding only downward through a trapdoor function via a dashed line.
The transform key 306 enables customized processing of the information stream via the transform-enabled hash operation 308, described previously in Figure 2 , and which is carried out by the transform-enabled hashing core 106 of Figure 1 . Thus, other users, such as the second user 112, process input messages into transformed hashes as previously described if they know the transform key 306 or have an instance of the transform-enabled cryptographic circuit 100 that internally stores the transform key 306 without providing external access or visibility. However, knowledge of the transform key 306 alone does not enable the ownership, e.g., creation or replication, of an information stream, as that requires the user passphrase 302. Figure 3 thus denotes the output value 214 as proceeding only downward through a trapdoor function via a dashed line.
In one embodiment therefore, the user passphrase 302 enables creation of a blockchain, while the transform key 306 enables others who do not know the user passphrase 302 to nevertheless process and verify input messages 202 such as blockchain headers. Further, knowledge of the transform key 306 enables the creation of any number of transform-enabled cryptographic circuits 100 for processing input messages 202, if the formulation of the programmable transformation function 208 is known.
The formulation of the programmable transformation function 208 is published in many cases, or it may be kept obscured. The cryptographic strength of the embodiments does not rely on the secrecy of the programmable transformation function 208. The transform key 306 that controls the customization of the programmable transformation function 208 is also either kept secret or made public. However this choice depends on whether the second users 112 are intended to be able to process the information stream with only original programmed circuitry, or also with replicated or "cloned" circuitry. In some cases only members of a given group, such as a government or corporation or other set of the second users 112, are intended to have the capability to process a private information stream, so the transform key 306 may be a secret shared only with such intended parties. In other cases, the intent is for anyone to be able to process a public information stream without the requirement for a shared secret, so the transform key 306 may be made public.
The transform-enabled cryptographic circuit 100 that has been programmed to contain the transform key 306 determines a specific predetermined output value 214 by processing a specific predetermined test input message 202. The specific predetermined test input message 202 is a widely known or standardized string of given length. In various embodiments, the specific predetermined input message is all zeroes, or all ones, or a particular string of text that is easily remembered by a human user and readily converted to a string of binary numbers .
The specific predetermined output value 214 is a unique identifier of a given information stream from which input messages 202 originate. A second user 112 who possesses neither knowledge of the user passphrase 302 nor of the transform key 306 therefore nonetheless identifies a given information stream using an instance of the programmed transform-enabled cryptographic circuit 100. Such a second user 112 processes messages, but cannot make copies of the transform-enabled cryptographic circuit 100 that has been programmed to inaccessibly and invisibly contain the transform key 306. This ability to identify an information stream with no direct knowledge of the user passphrase 302 nor of the transform key 306 is particularly advantageous in certain use scenarios.
In one embodiment the information stream is a blockchain, and the predetermined output value 214 is a ChainID that uniquely identifies the blockchain. In the future, there may be a large number of different blockchains, so through a ChainID any second user 112 with a programmed transform-enabled cryptographic circuit 100 distinguishes the blockchain from which input messages 202 originate from all others.
The ChainID is thus the lowest derivation level of the information hierarchy 300. The ChainID does not enable the creation of a blockchain (that requires knowledge of the user passphrase 302), and does not by itself enable the ability to replicate the programmed transform-enabled cryptographic circuit 100 (that requires knowledge of the transform key 306 by the second user 112 which may not be accessible or visible from the programmed transform-enabled cryptographic circuit 100). The ChainID functionality does however enable the easy identification of the blockchain.
Thus, the information hierarchy 300 separates out the ability to create a blockchain, interact with it, and identify it. Someone who knows only the transform key 306 but not the user passphrase 302 cannot create a blockchain , but can identify and verify it. Such verification is the basis of a proof-of-work system, e.g. bitcoin mining, although this disclosure is not limited in that regard.
At 402, the methodology 400 initially determines if a user knows the user passphrase 302. If so, at 404 the user is granted full control over the information hierarchy 300, and is thus equivalent to the first user 110 as previously described. Such a user is provided with the ability to create a new unique information stream, such as a blockchain . The user proceeds to create an information stream by customizing the programming of a transformation function and using the transform-enabled cryptographic circuit 100 to create blockchain block headers . The headers include a field indicating the particular validation method to be used for corresponding message content.
If the user does not know the user passphrase 302, the methodology 400 proceeds to 406. At 406, the methodology determines if the user knows the transform key 306. If so, the user, at 408, is granted the further privilege of programming additional instances or copies of transform-enabled cryptographic circuits 100. The programming occurs during a manufacturing process or thereafter.
If the user does not know the transform key 306, the methodology 400 proceeds to 410. At 410, the methodology 400 determines if the user at least has a programmed transform-enabled cryptographic circuit 100 to process an information stream that has been created in view of the technology described in this disclosure. If so, then at 412, the methodology 400 processes a predetermined test input message 202 to produce a predetermined output value 214 that serves as a ChainID. The ChainID indicates a particular information stream, such as a blockchain, from which input messages originate.
At 414, the methodology 400 enables the processing of other input messages from the information stream. In one embodiment, the information stream is a blockchain, and the processing comprises verification of the blockchain through computation of transform-customized hashes for subsequent comparison. If the user does not have a programmed transform-enabled cryptographic circuit 100, then an information stream that has been created in view of the technology described in this disclosure cannot be processed nor identified by the user.
The present inventor has realized, among other things, that particular circuitry advantageously secures the programming of the transform-enabled cryptographic circuit 100. Such particular circuitry enables the first user 110 to provide to the transform-enabled cryptographic circuit 100 with a copy of the user passphrase 302 which is used to generate the unique configuration key 108 for the cryptographic circuit 100. Similarly, the circuitry enables the derivation of the transform key 306 from the configuration key 108 in those cases where the transform key 306 is not the same as the configuration key 108.
In either case, storage of the transform key 306 in the circuitry in isolation, e.g., in a manner that is neither accessible nor visible externally, serves to enable enforcement of part of the information hierarchy 300 previously described. That is, if the first user 110 has knowledge of the transform key 306 during or after its generation, that user is permitted to replicate circuitry (or executable instructions) that implements the particular customized transform-enabled hashing used to process input messages 202. In contrast, if the second user 112 does not have knowledge of the transform key 306 but simply has access to circuitry that invisibly stores the transform key 306 in isolation, such second user 112 is permitted to process input messages but is not permitted to replicate the circuitry. That is, the invisible, inaccessible, and indelible isolated storage of the transform key 306 prevents the circuitry from being "cloned". The processing of input messages 202 includes identifying a given information stream and verifying messages from the information stream , as previously described, whether by circuitry or executable instructions.
Hardware based enforcement of the management of the information hierarchy 300 not only enables different users to be granted different levels of control of the information hierarchy 300, it also limits the availability of the transform key 306. If the first user 110 who has the user passphrase 302 wants to generate a transform key 306, that does not necessarily mean that the first user 110 wants to have actual knowledge of the transform key 306, or even knowledge of how the transform key 306 is derived from the user passphrase 302. The first user 110 may not want to be capable of determining the transform key 306 at all.
Instead, the first user 110 may simply wish to create hardware that only generates and securely stores the transform key 306 internally, that is, in isolation, to enable input message processing and information stream identification by second users 112. The particular methodology for generating the transform key 306 from the user passphrase 302 thus may not need to be known even to the first user 110 who has control of the entire information hierarchy 300.
Similarly, particular circuitry better protects the user passphrase 302 that enables complete control of the entire information hierarchy 300. That is, the first user 110 provides the user passphrase 302 to the transform-enabled cryptographic circuit 100, but that circuit 100 deletes the user passphrase 302 as soon as derivation of the configuration key 108 and/or transform key 306 has been completed and the key value or values are indelibly and inaccessibly stored within the circuit 100.
The patent application previously mentioned, US2017/0206382 A1 , provides further detail on the various one-time programmable memory technologies that may store information in circuitry. These technologies include but are not limited to micro-fuses, anti-fuses, non-volatile random access memories including but not limited to flash memory or other types of non-volatile memory. In general, determination of the state of each element of such memories via external physical examination is intentionally very difficult or infeasible.
Software based implementations of the transform-customized message hashing process previously described are also within the scope of this disclosure. However, hardware based implementations are more immune to monitoring during operation. The undesirable consequences of such monitoring include the eventual discovery of the user passphrase 302, the transform key 306, as well as the transform key generation 304 methodology.
Hardware implementations therefore offer better enforcement of the restricted creation of information streams, such as blockchains, based on the secrecy of the user passphrase 302. Hardware implementations also offer better enforcement of the restricted ability to replicate transform-customized hashing circuitry, based on the availability of the transform key 306. This disclosure therefore provides a novel self-contained internally-programming circuit approach to hardware-based enforcement of the information hierarchy 300.
In this case, the integrated circuit 102 receives a copy of the user passphrase 302 from the first user 110 via the programming and configuration interface 104 previously described. The programming and configuration interface 104 acts as a "black box" that accepts certain inputs, but only outputs acknowledgements and does not echo the inputs provided. That is, the programming and configuration interface 104 does not allow access to or visibility of the isolated internal operations of the integrated circuit 102.
The integrated circuit 102 then generates the transform key 306 according to a transform key generation 304 methodology embedded in its circuitry. The first user 110 is aware of the transform key generation 304 methodology in some embodiments, or the first user 110 is not aware of the transform key generation 304 methodology in other embodiments. Note that transform key 306 is the same as the configuration key 108 or is derived from the configuration key 108 as previously described.
The integrated circuit 102 then stores the generated transform key 306 in an indelible and hidden manner, and deletes its copy of the user passphrase 302. In one embodiment, the transform key 306 is stored in a one-time programmable memory 502, which comprises an array of micro-fuses or anti-fuses or various types of non-volatile memory. Micro-fuses are generally short circuits until they are effectively "blown" open (e.g., rendered nonconductive), typically by application of a voltage pulse of particular magnitude and duration. Anti-fuses in contrast are generally open circuits until they are effectively "burned" closed (e.g., rendered conductive), typically again by application of a voltage pulse of particular magnitude and duration. These state changes do not result in physical changes that are readily visible.
The integrated circuit 102 provides an acknowledgement 504 to the first user 110 to denote at least one of the receipt of the user passphrase 302, the deletion of the user passphrase 302, and the successful completion of the storage of the transform key 306 into memory 502. Thus, the conceptual shopkeeper effectively provides the internally-programmed integrated circuit 102 to the customer (e.g., the first user 110) after having customized it in isolation, e.g., without any customer access or visibility into the programming process.
The approach provided offers the first user 110 the advantage of trusting the hardware implementation with the user passphrase 302 for only a limited time, because the hardware implementation will not store the user passphrase 302 once the transform key 306 has been generated and stored internally. Further, the first user 110 knows that the hardware implementation is relatively secure from attack. That is, a hacker may be able to dismantle the integrated circuit 120 to attempt to determine the transform key generation methodology and the programmable transformation function, but the security of the system does not depend on knowledge of either.
Recovery of the actual transform key 306 (which was generated from the now-deleted user passphrase 302 and stored in the one-time programmable memory 502), which is required for cloning of the integrated circuit 102, is generally infeasible via physical examination. Further, a hacker may have to destroy a new copy of the programmed integrated circuit 102 with every hacking attempt, which would rapidly become expensive.
With current semiconductor fabrication processes, the incorporation of flash memory onto the same integrated circuit as logic circuitry is not presently available for processes that produce logic devices of less than 28nm feature size. Use of micro-fuses or anti-fuses therefore is advantageous, as they do not suffer from this process limitation. Both micro-fuses and anti-fuses may be placed in the datapath circuitry within the integrated circuit in such a manner as to result in a very limited performance overhead, thus retaining the advantages ASICs have over other types of solutions in terms of speed and efficiency.
The programming of the one-time programmable memory 502 is performed during the manufacture of the integrated circuit 102, or is performed subsequently, according to various embodiments. This feature enables the manufacture of "blank" or uncustomized integrated circuits 102 that are programmed by the first user 110 without requiring any trust of the manufacturer. External circuitry (which is not integrated with the integrated circuit 102) is designed to generate and apply a programming voltage pulse of predetermined magnitude and duration to store data into an element of memory 502. In some cases such programming voltages are higher than logic power supply voltages, so in some embodiments external circuitry generates such voltages, and applies them when triggered to do so by the integrated circuit 102.
The integrated circuit 102 steps through an indexed array of elements in the memory 502 to be programmed. The integrated circuit 102 signals the external circuitry when a targeted memory element has been electrically connected to an external pin that receives programming voltage pulses from outside the integrated circuit 102. Thus, even during programming, the transfer key 306 is not externally visible; only a set of internally-triggered externally-generated programming pulses is observable in such embodiments. Further, the timing of such trigger signals is varied to obscure such observations. Similarly, voltage pulses that do not actually program any memory elements are triggered to further obscure the programming process.
At 604, the process acknowledges receipt of the user passphrase. At 606, the process transfers the copy of the user passphrase 302 to the transform key generator 304. At 608, the process generates the transform key 306 with the transform key generator 304. In some cases, the transform key generator 304 generates the transform key 306 by applying a number of hashing operations (e.g., two applications of the SHA-256 hashing function) sequentially to the user passphrase 302, but this disclosure is not limited in that regard. In some cases, the configuration key 108 is derived from the user passphrase 302, and the transform key 306 is derived from the configuration key 108, but this disclosure is again not limited in that regard.
At 610, the process deletes the copy of the user passphrase 302. This ensures that the user passphrase 302 cannot be recovered by a hacker who may dismantle equipment that enforces the information stream management constraints. The deletion is acknowledged by the programming and configuration interface 104.
At 612, the process stores the transform key 306 indelibly and inaccessibly into one-time programmable memory 502. Maintenance of the secrecy of the transform key 306 prevents replication of the equipment that enforces the information stream management constraints. At 614, the programming and configuration interface 104 provides an acknowledgement to the programming user 110 that the customized programming process has been successfully completed.
The present inventor has realized, among other things, that the particular circuitry that advantageously secures the transform programming of the transform-enabled cryptographic circuit 100 in isolation may be improved. Rather than requiring external circuitry to provide programming pulses for changing states in elements of the one-time programmable memory 502, in some cases an ASIC instead handles all of the memory 502 programming tasks by itself. That is, all of the permanent on-chip storage tasks related to keeping the transform key 306 hidden in the memory 502 are performed by the same integrated circuit 102 that performs the various cryptographic functions previously described.
In one instance, an autonomous self-programming integrated circuit 102 has its own internal circuitry for permanently recording states into permanent on-chip storage. Internal voltage-boosting charge pump circuitry is integrated together with the logic circuitry on the same semiconductor chip to generate the voltages required to change memory 502 element states. Internal timer circuitry is also integrated on the same semiconductor chip, to apply the boosted voltages to selected memory 502 elements for a predetermined specified time. Applicable voltage-boosting and timer circuitry is familiar to one of ordinary skill in the art.
Such an integrated circuit 102 alone fully implements the conceptual "shopkeeper" previously described, who accepts only a user passphrase from a programming user (e.g., the first user 110). This arrangement provides several advantages over the arrangements previously described.
First, there would be no need to coordinate operations between the self-programming integrated circuit 102 and any external (not commonly-integrated) circuitry used for memory management. Specifically, there would be no need to provide an external pin that would receive the programming voltage pulses from any external circuitry outside the integrated circuit 102, nor an external pin to provide trigger signals to any external circuitry. Pin count for the integrated circuit 102 is therefore reduced, reducing circuit cost and complexity.
Second, the details of the programming voltage pulse magnitude and duration need not be made public . Such details may allow a hacker to infer what type of one-time programmable memory 502 elements are used in the integrated circuit 102 if publicized. That information could be useful in aiding a hacking attempt. Therefore, the autonomous self-programming integrated circuit 102 described herein is more secure than other programmable integrated circuits.
Finally, since no external circuitry is required for memory programming in this arrangement, overall system reliability is increased as there is less possibility that the integrated circuit 102 could be damaged during its programming. This aspect is particularly advantageous for arrangements in which the integrated circuit 102 is not programmed during manufacture but is instead programmed later, perhaps in a less well controlled environment.
In cases where a user, versus a manufacturer or vendor, performs the programming of one-time programmable memory 502 elements, circuit failures that may actually be due to the user may instead be blamed on the manufacturer or vendor. In such cases the user may return the integrated circuit 102 for a refund, falsely asserting that it was defective on arrival. The processing of such product returns constitutes a significant expense and unnecessarily puts the reputation of a manufacturer or vendor at risk. The use of autonomous self-programming bypasses this issue entirely.
The present inventor has realized, among other things, that the particular circuitry that autonomously secures the transform programming of the transform-enabled cryptographic circuit 100 in isolation is advantageous in a variety of different use scenarios. For example, an autonomous self-programming integrated circuit 102 permanently records into the one-time programmable memory 502 a variety of data regarding its history after manufacture. The integrated circuit 102 records instances in which excessive voltages were applied to one or more of its pins.
The integrated circuit 102 also records other data to memory 502 that is relevant to reliability, including but not limited to maximum sensed operating temperatures, and detected indications of damage that might be related to hacking attempts. Such events may occur regardless of whether the integrated circuit is programmed by external circuitry, but the probability of such events is greater when external circuitry is involved. The integrated circuit 102 therefore uses internal circuitry to store indicia of such events, even if the integrated circuit 102 is designed to have its transform key 306 programmed using internal circuitry.
If an integrated circuit 102 is returned, e.g., to a vendor or manufacturer, for a refund, the stored data regarding its history after manufacture is retrieved from the one-time programmable memory 502. That data supports a decision to provide a refund or replacement if it shows no unusual events or reliability-related conditions occurred after manufacture. Conversely, that data may indicate that unusual and probably-damaging events or conditions did occur after manufacture. If these events or conditions were likely due to a user's actions, as determined by the number and/or pattern of events or conditions, then a refund or replacement request is denied. The number of one-time programmable memory 502 elements is limited, so the data simply indicates a count of events meeting some predetermined threshold qualifications.
In general, the features of autonomous internal programming and isolated storage of cryptographic transform keys into one-time programmable memory, combined with the storage of historical circuit context information, advantageously resolve many communications security problems. A "reset replay" attack involves repeatedly resetting the power supply of a system and resuming a previous attack that might otherwise be ended when the attacked system has counted the attack attempts and taken countermeasures against further attacks. Such countermeasures comprise deleting data stored in non-volatile memory, ignoring all future access attempts for a span of time, or even activation of internal self-destruct mechanisms to render itself entirely inoperable. An attacked system that does not "remember" being previously attacked is less secure than one that does, and can respond accordingly.
Therefore, in one arrangement, a product comprising a number of integrated circuits that communicate with each other uses integrated circuits 102 that are capable of managing their own chip-to-chip communications security. An integrated circuit 102 stores context information into its one-time programmable memory 502 when it is first activated (e.g., at the foundry where it is fabricated), and subsequently stores various context information into its one-time programmable memory 502 thereafter so that it will remember its history even when powered off and restarted. The context information goes beyond indicia of events or conditions likely to cause damage, to include cryptographic data related to communications security.
In another arrangement, no context information is stored at the first activation of the integrated circuit 102 at all. Instead, a true noise-based random number generator onboard the integrated circuit 102 generates a number of cryptographic keys that are subsequently used to secure inter-chip communications. Thus, inter-chip communications between integrated circuits 102 within a given product is managed just as communications between unknown parties over an untrusted network are managed.
Various interfaces handle communications between the processor 702 and other parties, such as local user interface 714, locally connected process interface 716, and remotely connected process interface 718. A remote communications chip 720 handles data transfer between the remotely connected process interface 718 and the processor 702. Various processes 722 are executed by the processor 702.
A bulk non-voltage storage device 724, such as a flash storage integrated circuit also resides on the printed circuit board 704 and exchanges data with the processor 702. Other integrated circuits 726 and 728 are also mounted on the printed circuit board 704 and exchange data with the processor 702. For simplicity, the term "flash storage" in this description refers to any reprogrammable non-volatile memory technology, and is not necessarily limited to flash memory per se.
A local low-volume flash storage device 730 for sensitive data also resides on the printed circuit board 704. Communications link 732 transfers data between the low-volume non-volatile storage device 730 and the processor 702. Non-volatile storage device 730 comprises a flash memory, as noted.
In some conventional instances, some form of relatively lightweight cryptography is employed on either side of the communications link 732 to sensitive data flash storage device 730. In some instances, only certain portions of the processor 702 (sometimes referred to as a "secure zone" or security "sandbox") have access to the flash storage device 730 for sensitive data. This approach to communications security is fundamentally flawed, and vulnerable to the "reset replay" attack previously described. An improved approach is provided that uses the transform-enabled cryptographic circuit and one-time programmable memory previously described.
Unlike the local low-volume flash storage device 730, integrated circuit 830 includes not only a non-volatile storage block 832 but also a second secure communications circuit block 834, on the same semiconductor chip. The second secure communications circuit block 834 mediates all on-chip communications with the non-volatile storage block 832 and all off-chip communications 828 with the first secure communications circuit block 824. The second secure communications circuit block 834 has exclusive read/write access to its own one-time programmable memory, and includes internal circuitry for its programming.
Off-chip communications 828 comprise messages 906 from the first secure communications circuit block 824 to the second secure communications circuit block 834 inside integrated circuit 830, and messages 908 from the second secure communications circuit block 834 to the first secure communications circuit block 824. An outgoing communications circuit block 912 in the first secure communications circuit block 824 handles off-chip communications 828.
Control unit 914 comprises circuitry that coordinates the operations of the first secure communications block 824. Hashing block 916 calculates the results of a one-way function applied to an input. Fuse block 918 stores data into a one-time programmable memory, which includes micro-fuses, anti-fuses, or other non-volatile memory elements. Fuse block 918 uses internal circuitry to generate programming pulses, as previously described. Memory block 920 stores data used for managing communications security. Random number generator (RNG) 922 generates random numbers, as opposed to pseudorandom numbers, as will be described.
An incoming communications circuit block 1010 in the second secure communications circuit block 834 handles on-chip communications 836. An outgoing communications circuit block 1012 in the second secure communications circuit block 834 handles off-chip communications 828.
Control unit 1014 comprises circuitry that coordinates the operations of the second secure communications circuit block 834, and is similar to the control unit 914 of the first secure communications block 824. Hashing block 1016, fuse block 1018, memory block 1020, and random number generator 1022 are also similar to their counterparts in the first secure communications block 824.
In the arrangement of Figures 8-10 , communications between the processor 802 and the external storage 832 are cryptographically protected based on cryptographic keys stored in the one-time programmable memories of the secure communications blocks 824 and 834. Other security-related information useful for preventing a reset replay attack are also stored in the one-time programmable memories, and so would not be cleared during a power reset. The data is stored in the one-time programmable memories using internal circuitry, so there is no chance that the one-time programmable memory elements may be hacked by external means. The data stored in the one-time programmable memories and used in the one-way functions encode and validate messages going between the processor and the external non-volatile storage. Unlike the product 700 of Figure 7 , therefore, communications between the processor and the external non-volatile storage cannot be simply monitored or replaced with falsified messages.
Although logic circuitry and flash memory cannot presently be integrated on the same semiconductor chip if the logic devices are under 28nm in size, micro-fuses and anti-fuses may be integrated onto a flash memory chip. The secure communications circuit blocks are therefore able to include both logic circuitry below 28nm in size and one-time programmable memory elements comprising micro-fuses and/or anti-fuses.
At 1102, the methodology begins with a random number generator in a secure communications circuit block, such as the RNG 922 in the first secure communications circuit block 824 . Unlike a pseudorandom number generator, which produces numbers that appear to be random but are actually reproducibly predetermined by a particular algorithm, the RNG generates numbers that are indeed as random as possible for the methodology. In one example embodiment, the RNG amplifies noise from an electronic device, such as a reverse-biased diode, and feeds such amplified noise into a logic circuit to produce a substantially random stream of bits.
The RNG collects this stream of bits into a register of predetermined size to produce a random string of binary numbers. The register resides in the memory block 920 . The RNG further puts this random string of binary numbers through a one-way function or hashing algorithm as previously described, to further jumble the random string of binary numbers into an output random number that is in binary form and of a given length. The one-way function is implemented in the hashing block 916 . This hashing is advantageous if for some reason the RNG outputs a string of binary numbers that are all zeroes or all ones, which may prove cryptographically weak in some circumstances.
The output random numbers generated by the RNG serve a variety of cryptographic purposes. The output random number comprises a user passphrase for controlling an information stream, as previously described. The output random number also comprises a nonce, or arbitrary single-time use number for creating secure communications sessions between communicating parties by excluding the possibility of replay attacks. The output random number is also used as a cryptographic key. The output random number is also used as a salt that is concatenated onto other output random numbers used for various purposes.
At 1104, the methodology stores the output random numbers generated by the RNG into the one-time programmable memory of the secure communications circuit block, such as fuse block 918 . The output random numbers are programmed into the one-time programmable memory elements using internal circuitry that generates the programming pulses. The stored random numbers are thus not externally visible or accessible, but may be useable only by the corresponding secure communications circuit block, such as the first secure communications block 824 .
At 1106, the methodology transmits at least one of the output random numbers another secure communications circuit block, such as the second secure communications block 834 . More generally, the output random numbers are transmitted to any number of other secure communications circuit blocks, which include those in other products . At 1108, the methodology stores the transmitted random numbers into corresponding one-time programmable memories of the other secure communications circuit blocks.
At 1110, in one example, a first integrated circuit, such as the first secure communications circuit block 824, generates two random sets of public-private key pairs. The first integrated circuit then programs one of the private keys and both of the public keys into its one-time programmable memory using its internal programming circuitry. The first integrated circuit then transmits the other private key and both of the public keys to a second integrated circuit, such as the second secure communications circuit block 834. The second integrated circuit then programs the private key it has received, and both of the public keys it has received, into its one-time programmable memory using its internal programming circuitry.
All subsequent communications between the first integrated circuit and the second integrated circuit, after trust has been established between them, utilize the public-private key functionality for secure communications. The initial storage and exchange of the context information (e.g., the cryptographic keys) occurs at the factory where a particular product 800 is manufactured. When a printed circuit board is first populated with its various integrated circuits, the processor triggers the methodology and secure non-volatile storage integrated circuits respond. The initial storage and exchange of the context information occurs later however, such as when a new user first uses the product.
At 1112, in another example, the methodology uses symmetric keys in place of the public-private key pairs previously described. In a further example, the methodology uses the private-public key pairs to exchange a randomly-generated short-term symmetric key, as is currently done in the HTTPS protocol to create a secure channel over an insecure network. This approach is therefore a combination of the operations 1110 and 1112.
At 1114, in another example, a first integrated circuit, such as the first secure communications circuit block 824, transmits an authorization request to a second integrated circuit, such as the second secure communications circuit block 834, along with a random number as an initial challenge. The second integrated circuit responds with the initial challenge, a transform-modified hash of the initial challenge, and a new random number as a second challenge. The first integrated circuit responds with all the data it received from the second integrated circuit, plus a transform-modified hash of the second challenge.
The initial challenge is sent as cleartext in this example, but that does not matter because it is the transform-modified hash of that number that is used as a block cipher by both sides. This secure communications initialization process occurs when the printed circuit board is first populated with the various integrated circuits, as previously described. In one example, the initial establishment of secure communications occurs via direct wiring, while subsequent communications are via wireless means (including optical). The initialization also occurs thereafter.
Although described in terms of only two secure communications circuit blocks, the methodology is not so limited. The methodology builds a secure network of any number of integrated circuits. In one example, the methodology treats one integrated circuit as a master that always initiates the secure communications methodology, and treats the other integrated circuits as slaves that respond to the initiation request but do not initiate such requests, but the disclosure is not limited in this regard. Further, the methodology builds a secure network of products in a network as well, with each product potentially having previously secured its own internal network.
The secure communications methodology described enables the processing of an information stream, which comprises a blockchain.
The present inventor has realized, among other things, that the transformed hash calculator may create a unique cryptographically defined and verifiable processor identifier or "CpuID" for each ASIC instance. The CpuID enables a particular hardware originator of an information stream or message to be reliably determined. This contrasts with the use of a ChainID to reliably denote a particular information stream or network destination, as previously described.
The distinction in this arrangement, at 1202, is that the configuration key 108 is based on a manufacture date, a wafer lot number, a wafer number, x and y (row/column) coordinates or indices for each die on a wafer, or on other data provided by the foundry in a user passphrase. At 1204, the ASIC generates a transform key with a transform key generator and deletes the user passphrase as previously described. At 1206, the configuration key 108 for each ASIC, or a transform key derived therefrom, is stored into a one-time programmable memory in the ASIC in isolation by a foundry that manufactures the ASIC.
Each ASIC instance therefore generate generates the unique CpuID whenever needed, at 1208, merely by processing the predetermined input message 202. The CpuID allows a given ASIC instance to be securely and remotely identified across an untrusted network. The predetermined input message 202 is a commonly known and widely used or even standardized "identify yourself' interrogation command string, or a customized challenge message.
Although the ASIC described is used to process an information stream at high speed, a simplified and thus inexpensive version may suffice when its primary function of interest is to administer secure data. That is, the CpuID calculating hardware is a stripped-down relatively slow version of the more general transform-modified OWF hardware previously described. It does not need to be implemented in the main datapath for high-speed calculations to serve as essentially a very cryptographically secure internal dongle. That is, the ASIC computes the CpuID to process an incoming message, such as an interrogation to prove that it has a valid transform block, or it uses the CpuID in an outgoing message, at 1210, to identify which ASIC instance originated the outgoing message.
The particular ASIC that establishes a new information stream, such as a blockchain, is considered an "author" of the information stream. Similarly a particular ASIC that creates a new message such as a blockchain entry is identified as the "author" of the entry. An ASIC used to process blockchains is directly identified as the processor that performed the work that is the basis of a proof-of-work system. This is distinct from the present bitcoin-related practice of identifying a person who claims to have done the work.
As a result, at 1212, this feature enables monitoring of which ASICs have been mining a given blockchain, to pay contracted miners who have been issued processors by a contractor to perform prescribed work for that contractor. Similarly, if an unknown person is mining a blockchain with unauthorized ASICs, intrusion detection is possible via the CpuID feature. Since no user passphrase is passed around, there is no chance that a bogus clone copy of the blockchain could be created, unless the one-way function is defeated. That possibility is very unlikely, since the one-way function always throws away some information and leaves only a noisy-appearing but verifiable residue behind.
The CpuID calculator is useful in consumer electronics items. An ASIC is used in a phone so that the manufacturer or reseller could burn a transform block into each such device for tracking purposes. Such devices are linked to other devices or accounts in a network; the phone is securely and verifiably linked to a license in a music distribution system (which itself may be identified by a specific ChainID). This hardware-level internal security enables many different uses, essentially providing system administrator type access privilege control (e.g., read/write/copy/delete) to files on a memory card or at a network location, at 1214. This feature is useful for securely managing licensed software updates by software makers/vendors, such as those providing operating systems or anti-virus programs .
The present inventor has realized, among other things, that the transformed hash calculator may be used to verify that a given instance of a cryptographic ASIC is still valid, and can process input messages properly. That is, the transform integrity of the ASIC is verified using a few simple calculations and comparisons. This disclosure thus provides a cryptographic ASIC and method for autonomously storing a unique internal identifier into a one-time programmable memory in the ASIC in isolation, by a foundry or a user, for this purpose. The unique internal identifier comprises the CpuID previously described, or a user passphrase, transform key, or configuration key, or various combinations of these values that are necessary to correctly process input messages.
A mismatch however indicates the stored internal identifier value is invalid or has not yet been stored because the ASIC has not been programmed. In the latter case, at 1308, the ASIC issues an error message indicating that it needs to be programmed, and normal operations are halted to allow for such programming. However, a mismatch may also occur, at 1310, because one-time programmable memory components undergo natural aging, or because the stored internal identifier value has been altered, perhaps by damage from static electricity discharge or by unauthorized access attempts by hackers. In either case, a mismatch indicates the ASIC will not process input messages properly, and available corrective steps are required.
Normally, a programmed ASIC that is proven incapable of properly calculating a given transform value should be disabled so it cannot initialize, nor process messages erroneously, and an error message should be provided. However, the present inventor has recognized that the failure of a single copy of a stored internal identifier value to match a calculated internal identifier value need not doom the ASIC to this fate. In one example, at 1312, the ASIC instead compares the calculated internal identifier value to another copy or copies of the stored internal identifier value, and disregards unreliable copies of the stored internal identifier.
The ASIC, at 1314, also compares multiple copies of the stored identifier in a voting scheme to determine their validity. If two out of three stored identifier values match each other and a calculated identifier value, that is a reasonable indication that the third stored identifier value that does not match the calculated identifier value is invalid and should be disregarded. This feature helps assure a purchaser that the ASIC will be useful as along as a confirmed good copy of the stored internal identifier value is available in its one-time programmable storage. The confirmed valid lifetime of the ASIC thus is extended far beyond the useful lifetime of a single copy of the stored internal identifier. When the last confirmed good copy of the stored internal identifier is gone, the ASIC returns an error value at bootup, indicating the ASIC is hopelessly damaged, stopping the bootup process.
As used herein, the term set refers to any collection of elements, whether finite or infinite. The term subset refers to any collection of elements, wherein the elements are taken from a parent set; a subset may be the entire parent set. The term proper subset refers to a subset containing fewer elements than the parent set. The term sequence refers to an ordered set or subset. The terms less than, less than or equal to, greater than, and greater than or equal to, are used herein to describe the relations between various objects or members of ordered sets or sequences; these terms will be understood to refer to any appropriate ordering relation applicable to the objects being ordered.
The term tool refers to any apparatus configured to perform a recited function. Tools include a collection of one or more components and can also be comprised of hardware, software or a combination thereof. Thus, a tool can be a collection of one or more software components, hardware components, software/hardware components or any combination or permutation thereof. As another example, a tool can be a computing device or other appliance on which software runs or in which hardware is implemented.
As used herein, the term component describes a given unit of functionality that can be performed in accordance with one or more arrangements of the technology disclosed herein. As used herein, a component is implemented utilizing any form of hardware, software, or a combination thereof. One or more processors, controllers, ASICs, programmable logic arrays (PLAs), programmable array logics (PALs), complex programmable logic devices (CPLDs), FPGAs, logical components, software routines or other mechanisms are implemented to make up a component. Hardware logic, including programmable logic for use with a programmable logic device (PLD) implementing all or part of the functionality previously described herein, is designed using traditional manual methods or is designed, captured, simulated, or documented electronically using various tools, such as Computer Aided Design (CAD) programs, a hardware description language (e.g., VHDL or AHDL), or a PLD programming language. Hardware logic is also generated by a non-transitory computer readable medium storing instructions that, when executed by a processor, manage parameters of a semiconductor component, a cell, a library of components, or a library of cells in electronic design automation (EDA) software to generate a manufacturable design for an integrated circuit. In implementation, the various components described herein are implemented as discrete components or the functions and features described are shared in part or in total among one or more components. In other words, as would be apparent to one of ordinary skill in the art after reading this description, the various features and functionality described herein are implemented in any given application and are implemented in one or more separate or shared components in various combinations and permutations. Even though various features or elements of functionality are individually described or claimed as separate components, one of ordinary skill in the art will understand that these features and functionality can be shared among one or more common software and hardware elements, and such description shall not require or imply that separate hardware or software components are used to implement such features or functionality.
Where components or components of the technology are implemented in whole or in part using software, these software elements are implemented to operate with a computing or processing component capable of carrying out the functionality described with respect thereto. One such example computing component is shown in Figure 14 . Various embodiments are described in terms of this example-computing component 1400. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the technology using other computing components or architectures.
Computing component 1400 includes one or more processors, controllers, control components, or other processing devices, such as a processor 1404. Processor 1404 is implemented using a special-purpose processing engine such as a microprocessor, controller, or other control logic. Processor 1404 is connected to a bus 1402, although any communication medium can be used to facilitate interaction with other components of computing component 1400 or to communicate externally.
Computing component 1400 includes one or more memory components, simply referred to herein as main memory 1408. Random access memory (RAM) or other dynamic memory, is used for storing information and instructions to be executed by processor 1404. Main memory 1408 is also used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 1404. Computing component 1400 likewise includes a read only memory (ROM) or other static storage device coupled to bus 1402 for storing static information and instructions for processor 1404.
The computing component 1400 also includes one or more various forms of information storage mechanism 1410, including a media drive 1412 and a storage unit interface 1420. The media drive 1412 includes a drive or other mechanism to support fixed or removable storage media 1414. A hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a compact disc (CD) or digital versatile disc (DVD) drive (read-only or read/write), or other removable or fixed media drive is provided. Accordingly, storage media 1414 includes a hard disk, a floppy disk, magnetic tape, cartridge, optical disk, a CD or DVD, or other fixed or removable medium that is read by, written to or accessed by media drive 1412. The storage media 1414 includes a computer usable storage medium having stored therein computer software or data.
Information storage mechanism 1410 includes other similar instrumentalities for allowing computer programs or other instructions or data to be loaded into computing component 1400. Such instrumentalities include a fixed or removable storage unit 1422 and an interface 1420. Storage units 1422 and interfaces 1420 include a program cartridge and cartridge interface, a removable memory ( a flash memory or other removable memory component) and memory slot, a personal computer memory card international association (PCMCIA) slot and card, and other fixed or removable storage units 1422 and interfaces 1420 that allow software and data to be transferred from the storage unit 1422 to computing component 1400.
Computing component 1400 also includes a communications interface 1424. Communications interface 1424 allows software and data to be transferred between computing component 1400 and external devices. Communications interface 1424 includes a modem or softmodem, a network interface (such as an Ethernet, network interface card, WiMedia, IEEE 802.XX or other interface), a communications port (such as a USB port, IR port, RS232 port Bluetooth® interface, or other port), or other communications interface. Software and data transferred via communications interface 1424 is carried on electronic, electromagnetic (which includes optical) or other signals capable of being exchanged by a given communications interface 1424. These signals are provided to communications interface 1424 via a channel 1428. This channel 1428 carries signals and is implemented using a wired or wireless communication medium. A channel includes a phone line, a cellular link, an RF link, an optical link, a network interface, a local or wide area network, and other wired or wireless communications channels.
In this document, the terms "computer program medium" and "computer usable medium" are used to generally refer to media such as memory 1408, storage unit 1420, media 1414, and channel 1428. These and other various forms of computer program media or computer usable media are involved in carrying one or more sequences of one or more instructions to a processing device for execution. Such instructions embodied on the medium, are generally referred to as "computer program code" or a "computer program product" (which are grouped in the form of computer programs or other groupings). When executed, such instructions enable the computing component 1400 to perform features or functions of the disclosed technology as discussed herein.
Claims (15)
- A cryptographic integrated circuit (102) adapted to manage operations on an information stream, comprising:a transform key generator (304) configured to derive a transform key (306) from a temporary copy of a user passphrase (302);a one-time programmable memory (502) configured to store the transform key (306) using programming pulses from external circuitry, with the transform key (306) inaccessible from outside the cryptographic integrated circuit (102) after being stored;a first one-way function, OWF, circuit block (204) configured to generate a hash (206) of an input message (202);a programmable transformation function circuit block configured to be customized by the transform key (306) and to perform a customized transformation function comprising at least one of bit inversion and bit transposition, to transform the hash (206) of the input message (202) into a transformed hash (210); anda second OWF circuit block (212) configured to generate a second hash of the transformed hash (210) as an output result (214), wherein the information stream is a blockchain.
- The cryptographic integrated circuit of claim 1, wherein the transform key (306) enables at least one of identifying the information stream and processing the input message (202) from the information stream into the output result (214).
- The cryptographic integrated circuit of claim 1, wherein the transform key (306) is derived by processing the user passphrase (302) through at least one OWF circuit block.
- The cryptographic integrated circuit of claim 2, wherein the identifying comprises generating an identifier by processing a predetermined input message.
- The cryptographic integrated circuit of claim 1, wherein knowledge of the transform key (306) enables replication of the cryptographic integrated circuit (102).
- The cryptographic integrated circuit of claim 1, wherein the user passphrase (302) enables creation of the information stream.
- The cryptographic integrated circuit of claim 1, wherein the transform key (306) is derived and stored during manufacture of the cryptographic integrated circuit (102).
- The cryptographic integrated circuit of claim 1, wherein the transform key (306) is derived and stored after manufacture of the cryptographic integrated circuit (102).
- A cryptographic method implemented on a cryptographic integrated circuit (600) adapted to manage operations on an information stream, the method (600) comprising:deriving a transform key (306) from a temporary copy of a user passphrase (302);storing the transform key in a one-time programmable memory (502) using programming pulses from external circuitry, with the transform key (306) inaccessible from outside the cryptographic integrated circuit (102) after being stored;processing an input message (202) from the information stream by:hashing the input message (202);performing a customized transforming of the hash (206) of the input message (202), with the transforming customized based on the transform key (306) and comprising at least one of bit inversion and bit transposition, to obtain a transformed hash (206); andhashing the transformed hash (206) into an output result (214); andcreating the information stream based on the output result (214), wherein the information stream is a blockchain.
- The cryptographic method of claim 9, wherein the transform key (306) is derived by processing the user passphrase (302) through at least one one-way function, OWF.
- The cryptographic method of claim 10, wherein the transform key (306) is derived from the user passphrase (302) by a sequential application of at least two OWFs to the user passphrase (302).
- The cryptographic method of claim 9, further comprising identifying the information stream using an identifier generated by processing a predetermined input message.
- The cryptographic method of claim 9, wherein knowledge of the transform key (306) enables replication of the cryptographic method.
- The cryptographic method of claim 9, wherein the transform key (306) is derived and stored:during manufacture of a cryptographic integrated circuit (102) that executes the cryptographic method (600), orafter manufacture of the cryptographic integrated circuit (102) that executes the cryptographic method (600).
- A cryptographic system (102) comprised in an cryptographic integrated circuit adapted to manage operations on an information stream, the system comprising:means for deriving a transform key (306) from a temporary copy of a user passphrase (302);means for storing the transform key (306) in a one-time programmable memory (502) using programming pulses from external circuitry, with the transform key (306) inaccessible from outside the cryptographic integrated circuit (102) after being stored;means for processing an input message (202) from the information stream by hashing the input message (202), performing a customized transforming of the hash (206) of the input message (202), with the transforming customized based on the transform key (306) and comprising at least one of bit inversion and bit transposition, and hashing the transformed hash (206) into an output result (214); andmeans for creating the information stream based on the output result (214), wherein the information stream is a blockchain.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62/662,544 | 2018-04-25 | ||
| US15/975,615 | 2018-05-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK40048925A true HK40048925A (en) | 2021-12-10 |
| HK40048925B HK40048925B (en) | 2024-08-23 |
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