CN115499223A - A key exchange method, device, electronic equipment and storage medium - Google Patents

Abstract

The invention discloses a key exchange method, a key exchange device, electronic equipment and a storage medium, which are used for solving the technical problem that the conventional key exchange protocol cannot meet the requirements of various scenes. The invention comprises the following steps: receiving an exchange key generation request sent by the proposing party terminal; determining an exchange protocol according to the exchange key generation request; and carrying out key exchange on the proposing party terminal and the exchanging party terminal by adopting the exchange protocol.

Description

A key exchange method, device, electronic equipment and storage medium

technical field

The invention relates to the technical field of key authentication, in particular to a key exchange method, device, electronic equipment and storage medium.

Background technique

Today, millions of devices and servers on the Internet need to frequently exchange keys (encrypted sessions) in order to conduct sessions, which gave rise to the Key Exchange Protocol (KE). The key exchange protocol means that when both parties need to use a key to encrypt the session, in order not to expose the session key, the two parties cannot directly send the key, so by sending some public information of both parties, use this information to construct a two-party The same key k can be calculated from both private and public information. This key will not be known by a third party, because the private information of both parties is kept separately.

Traditional key exchange cannot resist man-in-the-middle attacks, simulation attacks, replay attacks, etc., so it is necessary to join the key exchange protocol with identity authentication, also known as authenticated key exchange (AKE), and the authenticated key exchange protocol should allow two Users establish a shared key and at the end of the agreement it is clear which user they are talking to. In the currently commonly used authentication key exchange protocols, the traditional method is to bind the public key with the user identity in the form of a digital certificate issued by the digital certification center CA. However, there is a need for a trusted third party in such an agreement: the digital certification center CA is responsible for distributing digital certificates, which makes the problem of centralization prominent. So the distributed authenticated key exchange protocol came into being. Existing technologies are generally based on block chains for realizing distributed authentication key exchange.

In general, these blockchain-based protocols provide a solution to the security issues posed by trusted third parties. However, they still have limitations. Some technologies propose building a new blockchain to implement a decentralized protocol, but maintaining a public blockchain is undoubtedly cost-prohibitive. Therefore, some technologies rely on off-chain centralized components to provide proofs of validity and fairness. There are also some technologies that use the Ethereum blockchain to implement authenticated key exchange protocols, but these only achieve static security properties. Different protocols implement different security features, which cannot meet the needs of various scenarios.

Contents of the invention

The invention provides a key exchange method, device, electronic equipment and storage medium, which are used to solve the technical problem that the existing key exchange protocol cannot meet the requirements of various scenarios.

The present invention provides a key exchange method, which is applied to the Ethereum block chain platform; the Ethereum block chain platform communicates with the proposer terminal and the exchange party terminal; the method includes:

receiving an exchange key generation request sent by the proposer terminal;

determining an exchange protocol according to the exchange key generation request;

Exchanging keys between the proposer terminal and the exchanging party terminal by using the exchange protocol.

Optionally, the exchange protocol includes a first exchange protocol, a second exchange protocol, and a third exchange protocol; the step of determining the exchange protocol according to the exchange key generation request includes:

Obtain protection conditions and retention conditions from the exchange key generation request;

When the protection condition is that protection is not required, and the preservation condition is no long-term preservation, determine that the exchange protocol is the first exchange agreement;

When the preservation condition is long-term preservation, determine that the exchange protocol is the second exchange agreement;

When the protection condition is that protection is required, determine that the exchange protocol is the third exchange protocol.

Optionally, the step of exchanging keys between the proposer terminal and the exchange party terminal by using the exchange protocol includes:

When the exchange protocol is the first exchange protocol, receive the random number sent by the proposer terminal;

Obtain the first identity information and the first public key of the proposer terminal;

sending the random number, the first identity information, and the first public key to the terminal of the exchanging party;

receiving the ciphertext and signature returned by the exchange party terminal; the ciphertext is obtained by encrypting the session key and the first identity information by the exchange party terminal; the signature is obtained by the exchange party terminal through the Obtained by signing the ciphertext with the second private key of the terminal of the exchanging party;

Acquiring the second identity information and the second public key of the exchanging party terminal;

sending the ciphertext, the signature, the second identity information, and the second public key to the proposer terminal; the proposer terminal is used to adopt the second identity information and the second The public key is used to verify the signature; it is also used to decrypt the ciphertext by using the first private key of the proposer terminal to obtain the session key.

Optionally, the step of exchanging keys between the proposer terminal and the exchange party terminal by using the exchange protocol includes:

When the exchange protocol is the second exchange protocol, receive the first public key, ephemeral public key, and first signature sent by the proposer terminal; the first signature is the preset first The private key is obtained by signing the ephemeral public key;

Obtain the first identity information of the proposer terminal;

sending the ephemeral public key, the first identity information, and the first public key to the exchanging party terminal;

receiving the session key ciphertext and the second signature returned by the exchanging party terminal; the session key ciphertext is that the ephemeral key is used to pair the session key after the exchanging party passes the verification of the first signature obtained by encrypting the second identity information of the exchanging party terminal; the second signature is obtained by signing the ephemeral key, the session key ciphertext, and the first identity information by the exchanging party;

Obtain the second public key and the second identity information of the exchanging party terminal;

sending the session key ciphertext, the signature, the second public key, and the second identity information to the proposer terminal; the proposer terminal is configured to adopt the second identity information and the The second public key is used to verify the signature; it is also used to decrypt the session key ciphertext by using the ephemeral private key of the proposer to obtain the session key.

Optionally, the step of exchanging keys between the proposer terminal and the exchange party terminal by using the exchange protocol includes:

When the exchange protocol is the third exchange protocol, receiving the first public key and the ephemeral public key sent by the proposer terminal;

sending the first public key and the ephemeral public key to the exchanging party terminal;

Receive the first ciphertext and the second ciphertext returned by the exchanging party terminal; the first ciphertext is that the exchanging party terminal uses the ephemeral public key to encrypt the first encryption key, the second encryption key and the session The key is obtained; the second ciphertext is obtained by encrypting the first signature and the second identity information of the exchanging terminal by the exchanging terminal using the first encryption key; the first signature Obtained by encrypting the first encryption key, the ephemeral key, and the first ciphertext for the switching terminal;

Sending the first ciphertext and the second ciphertext to the proposer terminal; the proposer terminal is used to decrypt the first ciphertext to obtain the first encryption key and the second encryption key and the session key; and use the first encryption key to decrypt the second ciphertext to obtain the first signature and second identity information; and the second encryption key, ephemeral key and first secret Sign the text to obtain a second signature; and encrypt the second signature and the first identity information of the proposer to obtain a third ciphertext;

receiving the third ciphertext sent by the proposer terminal, and sending the third ciphertext to the exchanging terminal; the exchanging terminal is configured to use the second encryption key to Decrypt the three ciphertexts to obtain the second signature and the first identity information, and verify the second signature.

The present invention also provides a key exchange device, which is applied to the Ethereum block chain platform; the Ethereum block chain platform communicates with the proposer terminal and the exchange party terminal; the device includes:

an exchange key generation request receiving module, configured to receive the exchange key generation request sent by the proposer terminal;

an exchange protocol determination module, configured to determine an exchange protocol according to the exchange key generation request;

A key exchange module, configured to exchange keys between the proposer terminal and the exchange party terminal by using the exchange protocol.

Optionally, the exchange protocol includes a first exchange protocol, a second exchange protocol, and a third exchange protocol; the exchange protocol determination module includes:

Obtain protection conditions and retention conditions from the exchange key generation request;

A first exchange protocol determination submodule, configured to determine that the exchange protocol is the first exchange protocol when the protection condition is that protection is not required and the maintenance condition is not long-term preservation;

A second exchange protocol determining submodule, configured to determine that the exchange protocol is the second exchange protocol when the storage condition is long-term storage;

A third exchange protocol determining submodule, configured to determine that the exchange protocol is the third exchange protocol when the protection condition is that protection is required.

Optionally, the key exchange module includes:

A random number receiving submodule, configured to receive the random number sent by the proposer terminal when the exchange protocol is the first exchange protocol;

The first identity information and the first public key acquisition submodule, configured to acquire the first identity information and the first public key of the proposer terminal;

A first sending submodule, configured to send the random number, the first identity information, and the first public key to the exchanging terminal;

The ciphertext and signature receiving submodule is used to receive the ciphertext and signature returned by the exchanging party terminal; the ciphertext is obtained by encrypting the session key and the first identity information by the exchanging party terminal; the The signature is obtained by signing the ciphertext by the terminal of the exchange party through the second private key of the terminal of the exchange party;

The second identity information and the second public key acquisition submodule, configured to acquire the second identity information and the second public key of the exchanging party terminal;

The second sending submodule is configured to send the ciphertext, the signature, the second identity information, and the second public key to the proposer terminal; the proposer terminal is configured to adopt the first The second identity information and the second public key are used to verify the signature; and are also used to decrypt the ciphertext by using the first private key of the proposer terminal to obtain the session key.

The present invention also provides an electronic device, the device includes a processor and a memory:

The memory is used to store program codes and transmit the program codes to the processor;

The processor is configured to execute the key exchange method described in any one of the above items according to the instructions in the program code.

The present invention also provides a computer-readable storage medium, where the computer-readable storage medium is used to store program codes, and the program codes are used to execute the key exchange method described in any one of the above items.

As can be seen from the above technical solutions, the present invention has the following advantages: the present invention discloses a key exchange method, which is applied to the Ethereum block chain platform communicating with the proposer terminal and the exchange party terminal, including: receiving the proposer terminal The exchange key generation request is sent; the exchange protocol is determined according to the exchange key generation request; the exchange protocol is used to exchange keys between the proposer terminal and the exchange party terminal. Through the embodiments of the present invention, different exchange protocols can be selected according to different scenarios, so as to meet the security requirements of different scenarios.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative efforts.

Fig. 1 is a flow chart of the steps of a key exchange method provided by an embodiment of the present invention;

FIG. 2 is a flowchart of steps of a key exchange method provided by another embodiment of the present invention;

Fig. 3 is a structural block diagram of a key exchange device provided by an embodiment of the present invention.

detailed description

Embodiments of the present invention provide a key exchange method, device, electronic equipment, and storage medium, which are used to solve the technical problem that existing key exchange protocols cannot meet the requirements of various scenarios.

In order to make the purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the following The described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to FIG. 1 . FIG. 1 is a flowchart of steps of a key exchange method provided by an embodiment of the present invention.

A key exchange method provided by the present invention is applied to the Ethereum block chain platform; the Ethereum block chain platform communicates with the proposer terminal and the exchange party terminal; specifically, the following steps may be included:

Step 101, receiving an exchange key generation request sent by the proposer terminal;

Ethereum is an open source public blockchain platform with smart contract functions, providing a decentralized Ethereum virtual machine through its dedicated cryptocurrency Ether to process peer-to-peer contracts.

In the embodiment of the present invention, the proposing terminal and the exchanging terminal are two parties performing key exchange.

The present invention first initializes some basic information for all legal users (assumed to be n),

The system generates a triple information idS, skS, pkS (S=1,...,n) for each of them, where idS represents the identity information of the Sth user, skS and pkS are a pair of symmetric key pairs, It can be used for both public key encryption operations and ECDSA public key signature operations. Finally, in the system initialization stage, the information that can be disclosed is uploaded to the chain (put the idS, pkS and paramS information on the blockchain blocks 1,...,n of the respective users, where paramS refers to the information on some blockchains Information needed for chain operations, such as contract address, etc.).

When receiving the exchange key generation request sent by the proposer terminal, the key exchange operation is triggered.

Step 102, determining the exchange protocol according to the exchange key generation request;

After receiving the exchange key generation request, the Ethereum blockchain platform can determine the confidentiality requirements of the proposer terminal, and at this time, the exchange protocol can be determined according to the exchange key generation request.

Step 103, using the exchange protocol to perform key exchange between the proposer terminal and the exchange party terminal.

After the exchange protocol is determined, key exchange between the proposer terminal and the exchange party terminal can be performed based on the exchange protocol.

The invention discloses a key exchange method, which is applied to the Ethereum block chain platform communicating with the terminal of the proposer and the terminal of the exchange party, including: receiving the exchange key generation request sent by the proposer terminal; generating the request according to the exchange key Determine the exchange protocol; use the exchange protocol to exchange keys between the proposer terminal and the exchange party terminal. Through the embodiments of the present invention, different exchange protocols can be selected according to different scenarios, so as to meet the security requirements of different scenarios.

Please refer to FIG. 2. FIG. 2 is a flow chart of the steps of a key exchange method provided by another embodiment of the present invention, which may specifically include the following steps:

Step 201, receiving an exchange key generation request sent by the proposer terminal;

Step 201 is the same as step 101, for details, please refer to the description of step 101, which will not be repeated here.

Step 202, obtaining the protection condition and the retention condition from the exchange key generation request;

Step 203, when the protection condition is that no protection is required, and the preservation condition is no long-term preservation, determine that the exchange protocol is the first exchange agreement;

Step 204, when the preservation condition is long-term preservation, determine that the exchange protocol is the second exchange agreement;

Step 205, when the protection condition is that protection is required, determine that the exchange protocol is the third exchange agreement;

In the embodiment of the present invention, different protection conditions and retention conditions correspond to different exchange protocols, and after obtaining the exchange key generation request, corresponding protection conditions and retention conditions can be obtained therefrom.

When the user's identity does not need to be protected and the exchanged key does not need to be stored for a long time, the first exchange protocol is selected. The first switching protocol has the fastest switching speed. When the keys exchanged by users need to be stored for a long time, the second exchange protocol is selected. The second exchange protocol can ensure that even if the exchanged key is lost, it will not cause security problems to operations performed using the key before. The third exchange protocol is chosen when the identity of the user performing the key exchange needs to be protected. Its exchange speed is relatively slow but can provide user's identity protection.

Step 206, using the exchange protocol to perform key exchange between the proposer terminal and the exchange party terminal.

After determining the adopted exchange protocol, the Ethereum blockchain platform can exchange keys between the proposer terminal and the exchange party terminal.

In an example, the step of exchanging keys between the proposer terminal and the exchanging terminal by using the exchange protocol may include the following sub-steps:

S11. When the exchange protocol is the first exchange protocol, receive the random number sent by the proposer terminal;

S12. Obtain the first identity information and the first public key of the proposer terminal;

S13, sending the random number, the first identity information, and the first public key to the terminal of the exchanging party;

S14. Receive the ciphertext and the signature returned by the terminal of the exchanging party; the ciphertext is obtained by encrypting the session key and the first identity information by the terminal of the exchanging party; signed to get;

S15. Obtain the second identity information and the second public key of the exchanging party terminal;

S16. Send the ciphertext, signature, second identity information, and second public key to the proposer terminal; the proposer terminal is used to verify the signature by using the second identity information and the second public key; it is also used to use the proposer terminal Decrypt the ciphertext with the first private key to obtain the session key.

In a specific implementation, the detailed process of key exchange using the first exchange protocol DAKE1 is as follows:

1. The proposer terminal O sends a generated random number r to the blockchain;

2. The exchanging party terminal C obtains r, the first public key pkO, and the first identity information idO from the blockchain, and then takes a random number as the session key, encrypts k and C’s idC with pkO, and obtains a ciphertext c= RSA.EncpkO(k, idC), and sign the ciphertext c with C’s private key skC, and get the signature sig=ECDSA.SigskC(r, c, idC); realize the binding of the session key and C, and sign The identity can be verified as C with pkC. Among them, the above-mentioned RSA.Enc and ECDSA.Sig refer to the encryption algorithm of RSA, the standard encryption scheme of cryptography, and the signature algorithm of ECDSA, the signature scheme, and the subscripts indicate the corresponding keys.

3. After obtaining the ciphertext c and signature sig, the second public key pkC and the second identity information idC from the block chain, the proposer terminal can use pkC to verify the signature. That is, calculate whether ECDSA.VerifypkC(sig,c,idC) passes. Decrypt c with the first private key skO saved by yourself, that is, calculate AES.DecskO(c), and the decryption result is (k, idC).

4. After completion, output the session key k as the exchange key.

DAKE1 protocol satisfies static security and explicit authentication security. When the proposer terminal O completes the protocol, the proposer terminal O can determine that the exchange party C is "online" because C must sign the message containing O's random number r. However, when C completes the protocol, there is no way for C to be sure of O because it does not contain O.

Static Security: In an authenticated key exchange protocol, it is first assumed that the exchange parties do not reveal any honest user's long-term key. Under this assumption, if the final exchanged key k is indistinguishable from a random number from the perspective of the adversary, it means that such an authenticated key exchange protocol has a static security property. And, even if the adversary sees session keys from other user instances, it should remain so.

Explicitly authenticated security: Explicitly authenticated security means that in an authenticated key exchange protocol, both parties to the key exchange can determine with whom it is communicating. For example, if the key k is shared between instances of the proposer terminal O and the exchange party terminal C, then the instance of C should be able to know through the exchange protocol that he is talking to O, and O should also know that he is talking to C to make a call.

In another example, the step of exchanging keys between the proposer terminal and the exchange party terminal by using the exchange protocol may include the following sub-steps:

S21. When the exchange protocol is the second exchange protocol, receive the first public key, ephemeral public key and first signature sent by the proposer terminal; the first signature is the first private key pair preset by the proposer terminal to the ephemeral public key signed to get;

S22. Obtain the first identity information of the proposer terminal;

S23. Send the ephemeral public key, the first identity information, and the first public key to the exchanging party terminal;

S24. Receive the session key ciphertext and the second signature returned by the terminal of the exchanging party; the ciphertext of the session key is the second identity of the session key and the terminal of the exchanging party using the ephemeral key after the exchanging party passes the verification of the first signature The information is obtained after encryption; the second signature is obtained by the exchange party signing the ephemeral key, the session key ciphertext and the first identity information;

S25. Obtain the second public key and second identity information of the exchanging party terminal;

S26. Send the session key ciphertext, signature, second public key, and second identity information to the proposer terminal; the proposer terminal is used to verify the signature by using the second identity information and the second public key; The ephemeral private key of the proposer decrypts the session key ciphertext to obtain the session key.

In a specific implementation, the detailed process of key exchange using the second exchange protocol DAKE2 is as follows:

1. The proposer terminal O randomly generates a short-lived key pair, and uses its own first private key to sign the short-lived public key pkR to obtain the first signature, and then sends the first public key pkO and the short-lived public key, the first signature, the first Identity information idO to the blockchain.

2. Terminal C, the exchange party, obtains pkR, pkO, idO, and the first signature from the blockchain, and then verifies the signature. Take k as the session key, encrypt the session key with the ephemeral key, and obtain the session key ciphertext RSA.EncpkR(k, idC), C signs the session key ciphertext, and obtain the second signature c, SigC(pkR, c, idO), and upload the second signature to the blockchain.

3. O obtains the session key ciphertext, the second signature, the second public key pkC of the exchanging party terminal and the second identity information idC from the blockchain, and then verifies the second signature.

4. After completion, output the session key k as the exchange key.

DAKE2 protocol satisfies static security, explicit authentication security and forward security. This is because in each operation of the second exchange protocol DAKE2, O will generate a new temporary key pair, and the user's long-term key is only used for signature, not encryption. Therefore, cracking a signing key does not allow an adversary to decrypt any information.

Forward security: The forward security feature requires that for any authenticated key exchange protocol, even if the exchanged key is leaked, the information previously protected by the key can continue to be kept secret and will not be decrypted. For example, if an attacker obtains a user's long-term key, the attacker can impersonate the user to continue the attack and cause a lot of damage. However, if the damage can be limited to the time during which the user's key is compromised, then at least the session keys generated before the compromise cannot be compromised. This additional security property is called forward security.

The implementation of DAKE2 requires the use of an ephemeral key pair, an encryption scheme and a signature scheme. One of the ephemeral key pairs is used to encrypt the session key, and the long-term key originally placed on the chain is used to perform signatures, one to sign the ephemeral key, and the other to sign the ciphertext encrypted with the ephemeral key. Therefore, the long-term key is only used for signing, and even if it is cracked, it will not affect the previous session, thus achieving forward security.

In the embodiment of the present invention, the step of exchanging keys between the proposer terminal and the exchange party terminal by using the exchange protocol may include the following sub-steps:

S31. When the exchange protocol is the third exchange protocol, receive the first public key and the ephemeral public key sent by the proposer terminal;

S32, sending the first public key and the ephemeral public key to the exchanging party terminal;

S33, receiving the first ciphertext and the second ciphertext returned by the exchanging party terminal; the first ciphertext is obtained by encrypting the first encryption key, the second encryption key and the session key by the exchanging party terminal using the ephemeral public key; the second The ciphertext is obtained by encrypting the first signature and the second identity information of the exchanging terminal by the exchanging terminal using the first encryption key; The text is encrypted to obtain;

S34. Send the first ciphertext and the second ciphertext to the proposer terminal; the proposer terminal is used to decrypt the first ciphertext to obtain the first encryption key, the second encryption key and the session key; and through the second An encryption key decrypts the second ciphertext to obtain the first signature and second identity information; and signs the second encryption key, the ephemeral key and the first ciphertext to obtain the second signature; and the second signature and The first identity information of the proposer is encrypted to obtain the third ciphertext;

S35. Receive the third ciphertext sent by the proposer terminal, and send the third ciphertext to the exchanging terminal; the exchanging terminal is used to decrypt the third ciphertext using the second encryption key to obtain the second signature and the second One identity information, and verify the second signature.

In the embodiment of the present invention, DAKE3 can be called a protocol with identity protection. The implementation of DAKE3 also requires the use of an ephemeral key pair, an encryption scheme, and a signature scheme. Among them, a short-lived key pair is used to encrypt the session key, while the long-term key originally placed on the chain is used to execute the signature, one signs the short-lived key, and the other signs the ciphertext encrypted with the short-lived key. Therefore, the long-term key is only used for signing, and even if it is cracked, it will not affect the previous session, thus achieving forward security. At the same time, in the design of identity protection, in addition to a session key k, DAKE3 needs to randomly generate two more random keys k1 and k2, which are used to encrypt their respective identities with AES to protect their identities.

In a specific implementation, the detailed process of key exchange using the third exchange protocol DAKE3 is as follows:

1. The proposer terminal O randomly generates an ephemeral key pair, and sends the first public key and the ephemeral public key to the blockchain.

2. The exchanging party terminal C takes k as the session key, and encrypts the ephemeral key with the first encryption key k1 and the second encryption key k2 as encryption keys, as follows:

Calculation: c←RSA.EncpkR(k,k1,k2), σ1←ECDSA.SigpkC(k1,pkR,c),

c1←AES.Enck1(σ1,idC), and send (c,c1) to the blockchain.

Among them, c is the first ciphertext, c1 is the second ciphertext, and σ1 is the first signature.

3. O gets (c, c1) from the blockchain, decrypts c to get (k, k1, k2), uses k1 to decrypt to get σ1, idC, and verifies σ1; O calculates σ2←ECDSA.SigP(k2, pk,c), c2← AES.Enck2(σ2,idO) and send c2 to the blockchain, where AES.Enc refers to the encryption operation using the AES symmetric encryption algorithm. Among them, σ2 is the second signature, and c2 is the third ciphertext.

4. C uses k2 to decrypt c2, obtains σ2 and idO, and verifies the signature.

5. After completion, output the session key k as the exchange key.

DAKE3 protocol satisfies static security, explicit authentication security, implicit authentication security, forward security and identity protection.

Implicit authentication security: Implicit authentication security means that in an authenticated key exchange protocol, one party cannot determine the identity of the other party. Sometimes an authenticated key exchange protocol with implicit authentication security is necessary for certain applications. For example, when a leader O completes the agreement for a session, he/she can be sure that C is online for the entire duration of the session run, and O can actually be sure that some instance of C has completed the agreement and holds the matching session key. However, when C completes the protocol, he/she cannot have such guarantees, not only may there be no instance of O with a matching session key, but also O may not even be online during the execution of the protocol, which is critical for some specific applications. Said more necessary.

Identity protection: Identity protection means that, unless the other party requests to reveal their identities, neither party in the protocol will reveal their identities during the interaction process of the authenticated key exchange protocol, that is, maintain the anonymity of identities. Note that identity protection also means that any adversary other than the parties to the protocol cannot learn the identity of one or both users running the authenticated key exchange protocol.

Further, corresponding to the three exchange protocols, the embodiment of the present invention also designs the smart contract data structure of the Ethereum block chain, and the embodiment of the present invention provides two Ethereum block chain smart contract structures, wherein structure 1 can Make DAKE1, DAKE2, and DAKE3 "explicitly" send messages to the blockchain, structure 2 enables DAEK3 to "implicitly" send messages to the blockchain, and the "explicit" means that anyone in the system can find out the message received the identity of the recipient, while "implicit" means that no one else can obtain the identity of the recipient of the message. The data structure is shown in Table 1 below:

Table 1

Further, corresponding to the above data structure, the embodiment of the present invention provides the following two smart contract algorithms for communication between the two parties, which are respectively called Algorithm 1 and Algorithm 2, where Algorithm 1 implements the write interface of blockchain data, Algorithm 2 implements the reading interface of blockchain data. The proposer terminal O can set a communication message for the opponent through Algorithm 1, and through Algorithm 2, the exchanging party terminal C can read the message set by the proposer terminal. The three protocols corresponding to the embodiment of the present invention operate through Algorithm 1 and Algorithm 2 between O and C, write and read data in the blockchain, and finally realize key exchange. Algorithm 1 is shown in Table 2, and Algorithm 2 is shown in Table 3.

Table 2

table 3

The invention discloses a key exchange method, which is applied to the Ethereum block chain platform communicating with the terminal of the proposer and the terminal of the exchange party, including: receiving the exchange key generation request sent by the proposer terminal; generating the request according to the exchange key Determine the exchange protocol; use the exchange protocol to exchange keys between the proposer terminal and the exchange party terminal. Through the embodiments of the present invention, different exchange protocols can be selected according to different scenarios, so as to meet the security requirements of different scenarios.

Please refer to FIG. 3 . FIG. 3 is a structural block diagram of a key exchange device provided by an embodiment of the present invention.

The embodiment of the present invention provides a key exchange device, which is applied to the Ethereum block chain platform; the Ethereum block chain platform communicates with the proposer terminal and the exchange party terminal; the device includes:

The exchange key generation request receiving module 301 is configured to receive the exchange key generation request sent by the proposer terminal;

An exchange protocol determining module 302, configured to determine the exchange protocol according to the exchange key generation request;

The key exchange module 303 is configured to exchange keys between the proposer terminal and the exchange party terminal by using an exchange protocol.

In an embodiment of the present invention, the exchange protocol includes a first exchange protocol, a second exchange protocol, and a third exchange protocol; the exchange protocol determination module includes:

Obtain protection conditions and hold conditions from the exchange key generation request;

The first exchange protocol determination submodule is used to determine that the exchange protocol is the first exchange protocol when the protection condition is that protection is not required and the maintenance condition is not long-term storage;

The second exchange protocol determination submodule is used to determine that the exchange protocol is the second exchange protocol when the storage condition is long-term storage;

The third exchange protocol determination submodule is used to determine the exchange protocol as the third exchange protocol when the protection condition is that protection is required.

In the embodiment of the present invention, the key exchange module includes:

The random number receiving submodule is used to receive the random number sent by the proposer terminal when the exchange protocol is the first exchange protocol;

The first identity information and the first public key acquisition submodule, configured to acquire the first identity information and the first public key of the proposer terminal;

The first sending submodule is used to send the random number, the first identity information, and the first public key to the terminal of the exchanging party;

The ciphertext and signature receiving submodule is used to receive the ciphertext and signature returned by the exchanging terminal; the ciphertext is obtained by encrypting the session key and the first identity information by the exchanging terminal; the signature is obtained by the exchanging terminal through the exchanging terminal. Sign the ciphertext with the second private key;

The second identity information and the second public key acquisition submodule, configured to acquire the second identity information and the second public key of the exchanging party terminal;

The second sending sub-module is used to send the ciphertext, the signature, the second identity information and the second public key to the proposer terminal; the proposer terminal is used to verify the signature by using the second identity information and the second public key; It is used to decrypt the ciphertext by using the first private key of the proposer terminal to obtain the session key.

In the embodiment of the present invention, the key exchange module includes:

The first public key, ephemeral public key, and first signature receiving submodule, used to receive the first public key, ephemeral public key, and first signature sent by the proposer terminal when the exchange protocol is the second exchange protocol; the first signature Obtained by signing the ephemeral public key with the preset first private key by the proposer terminal;

The first identity information acquisition sub-module is used to acquire the first identity information of the proposer terminal;

The third sending submodule is used to send the ephemeral public key, the first identity information and the first public key to the exchanging party terminal;

The session key ciphertext and the second signature receiving submodule are used to receive the session key ciphertext and the second signature returned by the terminal of the exchanging party; The key is obtained by encrypting the session key and the second identity information of the exchanging party terminal; the second signature is obtained by the exchanging party signing the ephemeral key, the session key ciphertext, and the first identity information;

The second public key and second identity information acquisition submodule is used to acquire the second public key and second identity information of the exchanging party terminal;

The fourth sending submodule is used to send the session key ciphertext, the signature, the second public key and the second identity information to the proposer terminal; the proposer terminal is used to use the second identity information and the second public key to perform signature Verification; it is also used to decrypt the session key ciphertext with the ephemeral private key of the proposer to obtain the session key.

In the embodiment of the present invention, the key exchange module includes:

The first public key and ephemeral public key receiving submodule, configured to receive the first public key and ephemeral public key sent by the proposer terminal when the exchange protocol is the third exchange protocol;

The fifth sending submodule is used to send the first public key and the ephemeral public key to the terminal of the exchanging party;

The first ciphertext and the second ciphertext receiving submodule are used to receive the first ciphertext and the second ciphertext returned by the terminal of the exchanging party; the first ciphertext is the first encryption key encrypted by the terminal of the exchanging party using a short-lived public key, The second encryption key and the session key are obtained; the second ciphertext is obtained by encrypting the first signature and the second identity information of the exchange terminal using the first encryption key by the exchange terminal; the first signature is obtained by the exchange terminal pair Obtained by encrypting the first encryption key, the ephemeral key and the first ciphertext;

The sixth sending submodule is used to send the first ciphertext and the second ciphertext to the proposer terminal; the proposer terminal is used to decrypt the first ciphertext to obtain the first encryption key, the second encryption key and the session a key; and decrypting the second ciphertext with the first encryption key to obtain the first signature and second identity information; and signing the second encryption key, the ephemeral key and the first ciphertext to obtain the second signature; and encrypting the second signature and the first identity information of the proposer to obtain the third ciphertext;

The third ciphertext receiving submodule is used to receive the third ciphertext sent by the proposer terminal, and send the third ciphertext to the exchanging party terminal; the exchanging party terminal is used to use the second encryption key to process the third ciphertext Decrypt to obtain the second signature and the first identity information, and verify the second signature.

The embodiment of the present invention also provides an electronic device, the device includes a processor and a memory:

The memory is used to store the program code and transmit the program code to the processor;

The processor is configured to execute the key exchange method according to the embodiment of the present invention according to the instructions in the program code.

The present invention also provides a computer-readable storage medium, where the computer-readable storage medium is used to store program codes, and the program codes are used to execute the key exchange method of the embodiment of the present invention.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, devices, or computer program products. Accordingly, embodiments of the invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, embodiments of the invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

Embodiments of the present invention are described with reference to flowcharts and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor or processor of other programmable data processing terminal equipment to produce a machine such that instructions executed by the computer or processor of other programmable data processing terminal equipment Produce means for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the The instruction means implements the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded into a computer or other programmable data processing terminal equipment, so that a series of operational steps are performed on the computer or other programmable terminal equipment to produce computer-implemented processing, thereby The instructions executed above provide steps for implementing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

Having described preferred embodiments of embodiments of the present invention, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be construed to cover the preferred embodiment and all changes and modifications which fall within the scope of the embodiments of the present invention.

Finally, it should also be noted that in this text, relational terms such as first and second etc. are only used to distinguish one entity or operation from another, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or terminal equipment comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements identified, or also include elements inherent in such a process, method, article, or end-equipment. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or terminal device comprising said element.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions recorded in each embodiment are modified, or some of the technical features are replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. A key exchange method is characterized in that the method is applied to an Ethernet house block chain platform; the Ethernet house block chain platform is communicated with the proposing party terminal and the switching party terminal; the method comprises the following steps:

receiving an exchange key generation request sent by the proposing party terminal;

determining an exchange protocol according to the exchange key generation request;

and carrying out key exchange on the proposing party terminal and the exchanging party terminal by adopting the exchange protocol.

2. The method of claim 1, wherein the exchange protocols comprise a first exchange protocol, a second exchange protocol, and a third exchange protocol; the step of determining an exchange protocol according to the exchange key generation request includes:

obtaining a protection condition and a holding condition from the exchange key generation request;

when the protection condition is that protection is not needed and the retention condition is that long-term storage is not available, determining that the exchange protocol is the first exchange protocol;

when the holding condition is long-term storage, determining that the exchange protocol is the second exchange protocol;

and when the protection condition is that protection is needed, determining that the exchange protocol is the third exchange protocol.

3. The method according to claim 2, wherein the step of exchanging keys between the presenter terminal and the exchange terminal using the exchange protocol comprises:

when the exchange protocol is the first exchange protocol, receiving a random number sent by the proposing party terminal;

acquiring first identity information and a first public key of the terminal of the proposing party;

sending the random number, the first identity information and the first public key to an exchanger terminal;

receiving a ciphertext and a signature returned by the exchange side terminal; the ciphertext is obtained by encrypting a session key and the first identity information by the exchange party terminal; the signature is obtained by the exchange side terminal signing the ciphertext through a second private key of the exchange side terminal;

acquiring second identity information and a second public key of the exchange party terminal;

sending the ciphertext, the signature, the second identity information and the second public key to the proposing party terminal; the proposing party terminal is used for verifying the signature by adopting the second identity information and the second public key; and the second private key of the proposing party terminal is used for decrypting the ciphertext to obtain the session key.

4. The method according to claim 2, wherein the step of exchanging keys between the presenter terminal and the exchange terminal using the exchange protocol comprises:

when the exchange protocol is a second exchange protocol, receiving a first public key, a transient public key and a first signature sent by the presenter terminal; the first signature is obtained by signing the transient public key by the proposing party terminal by adopting a preset first private key;

acquiring first identity information of the terminal of the proposing party;

sending the transient public key, the first identity information and the first public key to the exchanger terminal;

receiving a session key ciphertext and a second signature returned by the exchange side terminal; the session key ciphertext is obtained by encrypting the session key and second identity information of the terminal of the exchange party by adopting the transient key after the exchange party passes the verification of the first signature; the second signature is obtained by the exchange party signing the transient key, the session key ciphertext and the first identity information;

acquiring a second public key and second identity information of the exchanger terminal;

sending the session key ciphertext, the signature, the second public key and the second identity information to the presenter terminal; the proposing party terminal is used for verifying the signature by adopting the second identity information and the second public key; and the system is also used for decrypting the session key ciphertext by adopting the transient private key of the proposing party to obtain the session key.

5. The method according to claim 2, wherein the step of exchanging keys between the presenter terminal and the exchange terminal using the exchange protocol comprises:

when the exchange protocol is a third exchange protocol, receiving a first public key and a transient public key sent by the proposing party terminal;

sending the first public key and the transient public key to the exchanger terminal;

receiving a first ciphertext and a second ciphertext returned by the exchange side terminal; the first ciphertext is obtained by encrypting a first encryption key, a second encryption key and a session key by the switch side terminal by adopting the transient public key; the second ciphertext is obtained by encrypting the first signature and second identity information of the exchange party terminal by using the first encryption key; the first signature is obtained by encrypting the first encryption key, the transient key and the first ciphertext by the exchange terminal;

sending the first ciphertext and the second ciphertext to the providing side terminal; the proposing party terminal is used for decrypting the first ciphertext to obtain the first encryption key, the second encryption key and the session key; decrypting the second ciphertext through the first encryption key to obtain a first signature and second identity information; signing the second encryption key, the transient key and the first ciphertext to obtain a second signature; encrypting the second signature and the first identity information of the presenter to obtain a third ciphertext;

receiving the third ciphertext sent by the proposing side terminal, and sending the third ciphertext to the switching side terminal; and the exchange side terminal is used for decrypting the third ciphertext by adopting the second encryption key to obtain the second signature and the first identity information and verifying the second signature.

6. A key exchange device is characterized in that the key exchange device is applied to an Ethernet bay blockchain platform; the Ethernet house block chain platform is communicated with the proposing party terminal and the switching party terminal; the device comprises:

an exchange key generation request receiving module, configured to receive an exchange key generation request sent by the presenter terminal;

the exchange protocol determining module is used for determining an exchange protocol according to the exchange key generation request;

and the key exchange module is used for exchanging keys between the proposing party terminal and the exchanging party terminal by adopting the exchange protocol.

7. The apparatus of claim 6, wherein the exchange protocols comprise a first exchange protocol, a second exchange protocol, and a third exchange protocol; the exchange protocol determination module comprises:

obtaining a protection condition and a holding condition from the exchange key generation request;

a first exchange protocol determining submodule, configured to determine that the exchange protocol is the first exchange protocol when the protection condition is that protection is not required and the retention condition is that long-term storage is not performed;

a second exchange protocol determination submodule configured to determine that the exchange protocol is the second exchange protocol when the holding condition is long-term storage;

and the third exchange protocol determining submodule is used for determining that the exchange protocol is the third exchange protocol when the protection condition is that protection is required.

8. The apparatus of claim 7, wherein the key exchange module comprises:

a random number receiving submodule, configured to receive a random number sent by the presenter terminal when the exchange protocol is the first exchange protocol;

a first identity information and first public key obtaining submodule, configured to obtain first identity information and a first public key of the presenter terminal;

the first sending submodule is used for sending the random number, the first identity information and the first public key to an exchanger terminal;

the ciphertext and signature receiving submodule is used for receiving the ciphertext and the signature returned by the exchanger terminal; the ciphertext is obtained by encrypting the session key and the first identity information by the exchange side terminal; the signature is obtained by the exchange side terminal signing the ciphertext through a second private key of the exchange side terminal;

the second identity information and second public key obtaining submodule is used for obtaining second identity information and a second public key of the exchanger terminal;

the second sending submodule is used for sending the ciphertext, the signature, the second identity information and the second public key to the proposing party terminal; the proposing party terminal is used for verifying the signature by adopting the second identity information and the second public key; and the second private key of the proposing party terminal is used for decrypting the ciphertext to obtain the session key.

9. An electronic device, comprising a processor and a memory:

the memory is used for storing program codes and transmitting the program codes to the processor;

the processor is configured to perform the key exchange method of any one of claims 1-5 according to instructions in the program code.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium is configured to store a program code for executing the key exchange method of any one of claims 1-5.

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