JP2003521791A - Content protection from illegal duplication - Google Patents

Abstract

(57) Abstract: A sufficient number of data to be included in a dataset to discourage transmission of the entire dataset over a limited bandwidth communication path (130) such as the Internet. An item is selected (112). Each data item has one or more parts and together make up a complete data set. Each portion of the dataset is linked to another portion of the dataset, and the link of each portion is tied to that portion through the use of one or more watermarks. In displaying the material to be rendered, the presence of the complete data set is confirmed 126 by verifying the presence of the linked portion. For additional security, the links between the parts are constituted by a random selection of each linked part. To ensure that each linked part corresponds to the original part that was linked, each link determines that the retrieval of the linked part corresponds to the originally assigned linked part Contains the identifier of the linked part that can be used to If the identifier associated with the linked portion does not properly match the displayed linked portion, the display of the data items of the dataset is prevented. In the preferred embodiment, a closed linked list is constructed so that portions of the data set can be included in the validation process if necessary.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates primarily to the field of consumer electronics, and more particularly to the protection of copy protected content material.

2. 2. Description of Related Art Illegal distribution of copyright material deprives the copyright owner of the legal royalty for this material, and encourages suppliers of this illegally distributed material to continue its illegal distribution. Give a profit to do. Content materials intended to be copy protected, such as artistic expressions or other materials with limited distribution rights, due to the ease of information transfer provided by the Internet, are subject to widespread illicit distribution. Cheap. The MP3 format for storing and transmitting compressed audio files enables the widespread distribution of audio recordings as it can compress a 30 or 40 megabyte digital audio recording of a song into a 3 or 4 megabyte MP3 file. . Using a typical 56 kbps dial-up connection to the internet, this MP3 file can be downloaded to the user computer in minutes. Thus, a malicious person reads a song from the original legal CD, encodes the song into MP3 format, and places the MP3 encoded song on the Internet for widespread illegal distribution. Instead, the malicious person can
A dial-in service may be provided to download the 3-encoded song. The illegal copy of the MP3 encoded song is subsequently played by a software or hardware device, or decompressed and stored on a recordable CD for playback on a conventional CD player.

Several mechanisms have been proposed to limit the playback of copy protected content material. Safety Digital Music Initiative (SDMI) and others
Advocate the use of "digital watermarks" to identify authorized content material. EP0981901, "Embedding auxiliary data in signals", published March 1, 2000, discloses a technique for embedding watermarks in electronic material. Like paper watermarks, digital watermarks are embedded in the content material in a detectable and invisible manner. The audio reproduction of a digital music recording with a watermark, for example, is indistinguishable from the reproduction of the same recording substantially without a watermark. But,
The watermark detection device can distinguish these two records based on the presence or absence of the watermark. The absence of a watermark cannot be used to distinguish between illegal and legal material, as some content material is not copy protected and therefore does not contain a watermark. In contrast, the absence of watermark indicates content material that is legally freely copyable.

Other copy protection mechanisms can also be used. For example, European Patent EP 0906700, "Method and system for transmitting content information and related supplementary information", issued April 7, 1999, describes a watermark that controls the number of times protected material is shown. We present the technology of copyright material protection through the use of "tickets".

Accurate reproduction of the watermark material results in the watermark being reproduced in a copy of the watermark material. Inaccurate or lossy reproduction of the watermark, however, may not provide reproduction of the watermark in the lossy copy of the material. Some protection mechanisms, including those of SDMI, make use of this property of lossy reproduction, based on the presence or absence of appropriate watermarks, to distinguish legal material from illegal material. In the SDMI scenario,
Two types of watermarks are defined: strong "watermarks" and "fragile" watermarks, which carry a substantial portion of the original content material, such as MP3 encoding of audio recordings. It is expected to survive a lossy playback designed to: playback retains enough information to allow a reasonable performance of the original recording and also retains a strong watermark. Fragile watermarks, on the other hand, are expected to be destroyed by lossy playback or other illegal tampering.

In the SDMI mechanism, the presence of a strong watermark indicates that the content material is copy protected, and the absence or collapse of the corresponding brittle watermark indicates that when the strong watermark is present, it is copied. Protected material indicates that it has been tampered with in some way. SDMI-compliant devices are SDMI-compliant devices whose watermark collapses or is absent of copy-protected material for use in portable players.
Except when justified by "SDMI-guaranteed" processing, such as compression, with corrupted watermarks or with strong watermarks detected but no brittle watermarks Refuse to represent watermark material. For ease of reference and understanding, the term "representation" is used herein to include any processing or transmission of content material, such as playback, recording, converting, activating, storing, loading, and the like. Used for. This mechanism is MP3
Or it helps to limit the distribution of the content material via other compression techniques, but does not affect the distribution of counterfeit, unmodified (uncompressed) playback of the content material. This limited protection is considered to be commercially viable, as downloading inconvenient very large files, which is costly to obtain a song, tends to discourage theft of uncompressed content material. To be

SUMMARY OF THE INVENTION It is an object of the present invention to extend the protection of copy protected material to include protection of uncompressed content material. To this end, the invention provides a method for detecting plagiarism, a decoding method, a storage medium, an encoder and a decoder, as described in the independent claims. Advantageous embodiments are described in the independent claims.

Achieved by choosing to include a sufficient number of data items within a dataset to discourage transmission of the entire dataset over a limited bandwidth communication path such as the Internet. To be done. Each data item has one or more parts, all of which include the complete data set. Each portion of the dataset is linked to the other portion of the dataset, and the links of each portion are tied to that portion through the use of one or more watermarks. In displaying the material for presentation, the existence of the complete data set is confirmed by verifying the existence of the linked parts. For added security, the links between parts are constructed by a random selection of each linked part. To ensure that each linked part corresponds to the original part that was linked, determine that each link corresponds to the originally allocated linked part. Contains the identifier of the linked part that can be used to If the identifier associated with the linked part does not properly match the displayed linked part, the display of the data item of the dataset is prevented. In the preferred embodiment, a closed linked list is constructed so that parts of the data set can be included in the validation process if desired.

[0009]   The invention will be explained in more detail by way of example with reference to the accompanying drawings.

[0010]   Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions.

DETAILED DESCRIPTION OF THE INVENTION For ease of understanding, the present invention will now be described in the context of a digitally recorded song. As will be apparent to those skilled in the art, the present invention is applicable to any recorded information intended to be transmitted over a limited bandwidth communication path. For example, individual content material items may be data records in a large database other than songs in an album.

The theft of goods can be more discouraging than the value of goods stolen by making the theft time consuming and inconvenient. For example, locked safes are used to protect small valuables, as the effort normally required to steal safes exceeds the gain that can be expected from stealing safes. Michael Epstein
Filed March 28, 2001, entitled "Protecting Content from Unauthorized Copying by Guaranteeing the Existence of a Complete Dataset," US Patent Application No. US Pat. S. 0
9 / 537,815, Attorney roster number US000035 (disclosure 709999B)
Teach selecting and tying into a data item dataset that is large enough to discourage transmission of the dataset over a bandwidth limited communication system such as the Internet. The application teaches linking data items within a dataset by forming a watermark that includes the dataset complete parameters and embedding the watermark within each portion of each data item. The application teaches the inclusion of part specific parameters (random numbers assigned to each part) within the warmark.

The referenced application teaches the use of "out-of-band data" to include complete parameters or information that can be used to determine complete parameters. The partial watermarks are compared with this complete parameter to ensure that they are the same part that was used to form this complete parameter with that dataset. To minimize the possibility of forgery, the complete parameter is based on a hash of the composite value of the part-specific identifier. The referenced application also teaches digitally signed certificates and other techniques that rely on cryptographic techniques such as hashes and the like.

In accordance with the invention, self-indicating data that facilitates determining whether a complete data set exists, without using out-of-band data and without using cryptographic functions such as hash functions. Sets are used. If the complete dataset does not exist, further processing of the dataset's data items is terminated. In the context of digital audio recording, compliant playback or recording devices are adapted to refuse to represent individual songs without the complete contents of the CD. In uncompressed digital format, the time required to download an entire album on a CD can be expected to be over an hour, even at DSL and cable modem speeds, due to network load and other factors. . Thus, by requiring that the complete contents of the CD be present in uncompressed format, the possibility of plagiarism of songs via wide distribution over the Internet at a download "cost" of over an hour. Is substantially reduced.

FIG. 1 shows an exemplary block diagram of a protection system 100 according to the present invention. The protection system 100 includes an encoder 110 that encodes content material on a medium 130.
, Having a decoder 120 that represents the content material from the medium 130. Encoder 1
10 has a selector 112 for selecting content material from the source SRC, a binder 116 for building a complete confirmation structure, and a recorder 114 for recording the content material on the medium 130. For example, the selector 112 may be configured to select content material corresponding to the songs collected in the album. For ease of reference, each selected content material item is called a "data item" and the complete data item comprises a "data set". Each data item contains one or more pieces of data that make up the data item, and the entire piece also makes up the "data set." The binder 116 forms a data structure that constitutes the links between parts of the dataset, by which the complete dataset can be identified. The links of each part are tied to that part through the use of one or more watermarks. The recorder 114 suitably formats, encodes, and stores the data set, along with the aforementioned data structures, on the medium 130 using techniques conventional in the art.

In accordance with the present invention, the selector 112 selects a dataset until the size of the dataset is considered large enough to discourage subsequent transmission of the dataset over a limited bandwidth communication channel. Select the data item to be added to. This "unwilling size" is a subjective value and depends on the assumed available communication bandwidth, the losses caused by transmission, etc. Other criteria are also used to determine whether to add additional data items to the dataset. For example, if a data item corresponds to a song in an album set in which it resides, all songs, whether or not the size of the data set exceeds a determined demoralizing size, typically Added to the dataset. If all the songs in the album set have been selected, and if the criteria for disincentive size have not yet been reached, then other data items are selected to accumulate the required disintegrating size. To be done. For example, a data item with random data bits is added to the data set to increase its size. These random bits are typically stored as out-of-band data, CD-ROM data, etc. to prevent them from being played as audible sounds by conventional CD players.
Alternatively, the data item may include other sample songs or other image and video portions associated with the recorded content material provided to promote the sale of other albums. Similarly, promotional material such as an Internet access subscription program may also be included within the information recorded on the medium. These and other means of adding size to the dataset will be apparent to those of ordinary skill in the art of this invention.

The decoder 120 according to the present invention comprises a renderer 122 and a gate 124 controlled by an integrity checker 126. The renderer 122 is configured to retrieve information from a media reading device such as a CD reader 132. As is known in the art, the renderer 122 retrieves information by defining a position index,
Then, in response, the reader 132 provides the data located at the defined position index on the medium 130. A block read of data at successive locations on the medium 130 is performed by defining a location index and a block size.

The dotted line in FIG. 1 illustrates an example song extractor 142 that extracts a song from media 130 and communicates it to an example CD mimic 144. The CD replicator 144 is, for example, a software program that provides information in response to a conventional CD read command. Instead, the information received from the song extractor is written to CD media and provided to a conventional CD reader 132. As mentioned above, the song extractor 142 is likely to be used because the transmission of the complete content of the medium 130 is assumed to be discouraged by the intended large size of the content of the medium 130.

In accordance with the present invention, the integrity checker 126 is configured to obtain data from the medium 130, typically via the renderer 122, to determine if the entire data set is present. .

FIG. 2 illustrates an exemplary data structure 200 for accumulating data items within a dataset that facilitates determining whether a complete original set exists. Truck T
210 and partial S220 structures are shown and are consistent with conventional CD memory structures and other storage media. As shown, each track T210 has a different number of portions S220. In the exemplary data structure 200, each portion S220 includes a link 230 to another portion S in the data structure 200. In the preferred embodiment, the links 230 in each portion 220 are based on a random selection of the other available links. For example, in the first portion S (0,0) of the track T0, the portion S (0,0)
220a has a link La230a linked to the portion S (1,1) and the portion S (1,1) 220f on the track T1. This portion 220f has an associated link Lf 230f that links to portion (m, 0) at track Tm. In the preferred embodiment, the links constitute a closed linked list, such that the traversal of the links from the phosphorus to the links through the data set constitutes a closed loop. The first part, which in this example is the part S (0,0) 220a, which receives the random linked part, is held in reverse and randomly selected as the random selection process proceeds through the data set. Assign available parts to each linked part.
When all parts are assigned as linked parts, the first part is assigned as the linked part of the last part. For example, the portion S (1, n1) 220h in the example data structure 200 of FIG. 2 indicates the last linked portion of the dataset 200, and the linked portion Lh230h is the first portion S ( 0,0) 220a, thereby forming a closed linked list of all parts 220 of the dataset 200. The complete dataset 200 is identified by proceeding through the dataset 200 via link L230, and confirms that each linked part is present. By providing a random linked list, the difficulty of forming a forged shortened list containing the complete song is increased. To avoid substitution of link assignments, the linked list L230 of each portion 220 may be encoded, for example, with the linked track number as a strong watermark and the linked portion number within the track as a brittle watermark. It is preferably encoded as a mixture of strong and fragile watermarks, so that it is encoded. As mentioned above, a strong watermark is one whose removal causes substantial damage or destruction of the data in which the watermark is embedded, and a fragile watermark is one in which the data in which it is embedded is , Which causes damage or corruption when the data is modified or deleted, for example by compression.

FIG. 3 illustrates an exemplary alternative data structure 300 that facilitates further checking if the linked list and each linked portion has been modified or replaced. In the data structure 300, as in the referenced application, the random number R (T, S) 3
32 is assigned to each part S220 of each track T210, and the random number of the linked part R (L) 336 of each part is also assigned to each part S220. While the random closed linked list is traversed via the link 230 associated with the portion 220, the assigned linked portion random number R (L) 336 is the linked portion random number R. (T, S)
332. These random numbers are also encoded as watermarks embedded in the portion 220. These numbers are fragile watermarks because fragile watermarks consume less resources than strong watermarks, and fragile watermarks are more sensitive to changes such as compression of the partial data in which they are embedded. It is preferably encoded as a mark. Other arrangements of strong and brittle watermarks will be apparent to those skilled in the art of the present invention. Similarly, it is possible to use other methods of forming the identifier in each part by placing the function value of the number of one part and the number in its linked parts.

A description will now be provided regarding forming the example data structure 300 of FIG.
Data items are accumulated to compose a sufficiently large data set to discourage transmission of the data set over a limited bandwidth communication channel, such as downloading from the Internet. As each data item is selected, the portion containing the data item is assigned a random number used to identify the portion, and its size is added to the accumulated size of the data set. After accumulating a dataset of sufficient size, a random closed linked list of portions of the dataset is formed, as described above. One or more watermarks are formed for each portion, including a random number assigned to that portion, a linked portion, and a random number assigned to the linked portion. As mentioned above, a combination of strong and brittle watermarks is preferably used to encode the information associated with each part. This portion and the embedded watermark are recorded on a recording medium such as a CD.

Here, in order to determine the existence of a complete data set, the example data structure 300 of FIG. 3 is used to represent the data items of the data set in dependence on the existence of the complete data set. This will be explained. It is assumed that the rendering device detects the presence of copy-protected material, for example through the detection of watermarks or other markings on the material. The starting portion S is preferably randomly selected. Start part S
The watermark of is read. The watermark includes a link address defining the track number and the part number of the other part, and a random number associated with the part at the link address. The watermark of the linked part is read. This watermark includes a random number assigned to the linked part, its link address and an associated random number. The random number associated with the linked portion included in the start portion is compared to the random number included in the linked portion. If the random numbers are not equal, subsequent processing of the data item in the dataset, such as song playback, is terminated. As mentioned above, other linked identifier techniques can also be used, such as accumulating a random number in one part and a function value such as a hash of this number in the linked parts. is there. If an alternative encoding mechanism is used, the compression will be modified accordingly.

If the part identifiers are found to be equal, processing continues to proceed to the linked part. The matching of the part identifiers described above continues for each subsequent linked part until sufficient confidence is obtained that the complete data set exists. In this example, absolute trust is obtained by continuing until the linked part is the original starting part, which indicates that all links in the closed linked list have been processed. . However, reading each watermark is time consuming and may not allow the consumer a substantial delay before representing the song. In the preferred embodiment, the expression of the song begins immediately after a number of successful random number matches. Thereafter, if the presentation system can read the information from the medium faster than the material needs to be rendered, further linked partial watermarks are read and verified, Then, when a mismatch is found, the expression is terminated.

Other data structures and corresponding encoding and decoding processes will be apparent to those skilled in the art of the present invention. FIG. 4 shows an alternative data structure 600 that uses a randomly linked set of parts to confirm the existence of the complete data set. In FIG. 4, each portion 620 has an associated linked portion L634 and an associated random number R636. In this alternative exemplary embodiment, the linked portion 620 'is
Indicates a linked portion L634 'indicating a return to the portion 620 that has been linked. That is, the linked addresses L634, 634 'constitute a linked set of parts 620, 620'. In this data structure, a common random number R
636 is assigned to each part of the linked set of parts 620, 620 '. To determine if a complete data set exists, the randomly selected parts are tested by making sure that the random number of each part is equal to the random number of the linked parts. A range or approximate range of partial addresses can be determined, whereby the first "randomly selected part" is a viable part on the recording medium. For example, the media table-of-content is used to determine the feasible track address, and the table-of-content is an embedded fragile watermark or other safety that can be used to determine the validity of the table-of-content. Suppose you have a device. If the range cannot be determined, the first randomly selected portion is from the track selected for rendering. This way, a malicious person can “sing a song from the CD”
If the song extractor 142 (FIG. 1) is used for “clipping” and it is communicated over the Internet in a compressed or uncompressed format, the link confirmation will be in the original data set. For any link in the portion of the song that is linked to another portion of the song in the CD reader 132 or CD mimic 144, "track-
No part can be found. "If the CD replicator 144 responds to this confirmation request by impersonating the bogus part, the bogus part does not contain the appropriate random number watermark, and the complete The sex checker 126 excludes further representations of the cut song.

The absolute certainty that all parts are present, regardless of whether or not the selected song produces the first part for confirmation, depends on the list of tested parts and all This can be accomplished by maintaining confirmation that continues until the set is tested. This approach assumes that the range of partial addresses can be determined or estimated so that truncation of the dataset can be detected. If the selected song is used to initiate confirmation, the range of partial addresses can be assumed to be contiguous through the range of link addresses within the selected song. For example, one link address is track 10, part 9
, Then each part 0 to 9 of track 10 is checked and then part 0 of tracks 0 to 10 is checked. These and other techniques for filling the search area will be apparent to those skilled in the art of this disclosure.

In a preferred embodiment, in order to justify the decision with a substantial statistical certainty, in order to minimize the time required to determine that a complete data set exists. The set of random parts is tested until sufficient reliability is obtained. That is,
For example, if half the data set is actually present, random selection of the first part from within the total range of all parts is likely to detect the absence of this part 50% of the time, If this part is present, the probability that the linked part is present is 50%. Thus, the successful set-test provides 75% confidence that there is at least half the data set. Each successive test is
Either the confidence level or the expected percentage that the dataset exists, or
Increase both. Statistical testing generally involves a number of appropriate sets to achieve a desired level of confidence that a given percentage of the dataset exists.
Can be used to determine a test. In an exemplary embodiment, confirmation of at least five randomly selected sets is considered sufficient to determine the presence or absence of the complete data set.

The foregoing merely illustrates the principles of the invention. It will be appreciated by those skilled in the art that it is possible to devise various combinations, which are not explicitly shown here, but which embody the principles of the invention and are within the scope of the invention. For example, the above example shows that each piece of recorded material is part of a data set. In an alternative embodiment, for efficiency, the selected data item or selected portion of the data item is
It can be used to construct a dataset. For example, the end of a song is not part of the "data set" defined herein, as the watermarking process may be based on a fixed block size for each watermark or each redundant copy of the watermark. For example, if the Warmark or other parameter requires tens of seconds of recording for reliable embedding, then the remainder of (modulo (10 seconds) (length of song)) is on the medium. However, it is not included in the "data set" whose integrity is checked. Similarly, some promotional material may be included on the recording medium, but may be intentionally excluded from the dataset so that it may be freely copied and represented anywhere. Example flow diagrams are presented for ease of understanding, and specific arrangements and sequences of steps are provided for purposes of explanation. For example, simple equivalence is shown in the decision block for determining a match, while depending on the particular technique of encoding or decoding the parameters, whether the read item matches the determined item. The evaluation as to whether or not to include may include various intermediate processes. These operations may be performed, for example, on items based on specific keys, fuzzy logic, or static tests to determine if two values are "close enough" to imply correspondence and the like. Including decryption. These and other variations will be apparent to those of ordinary skill in the art to which the present invention pertains and are within the scope of the claims. In the claims, any reference signs placed between parentheses shall not limit the claim. The word "comprising" does not exclude the presence of other elements or steps than those listed in a claim. The invention can be carried out by means of hardware which comprises several characteristic components and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that these measures are not used to advantage.

[Brief description of drawings]

FIG. 1 illustrates an exemplary system for protecting copy protected content material in accordance with the present invention.

FIG. 2 illustrates an exemplary data structure that facilitates determining the existence of a complete data set in accordance with the present invention.

FIG. 3 illustrates an exemplary alternative data structure that facilitates determining the existence of a complete data set and identifying portions within a data set in accordance with the present invention.

FIG. 4 illustrates an exemplary alternative data structure that facilitates determining that a complete data set exists, based on a statistical degree of certainty, in accordance with the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 20/10 H04N 1/387 H04N 1/387 G10L 9/00 E 1/40 H04N 1/40 Z (81 ) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, TR), CN, JP ( 72) Inventor Epstein, Michael A. Netherlands, 5656 Aer Eindouven, Plov Holstraan 6 F Term (reference) 5B017 AA06 BA09 CA16 5B057 CB19 CE08 CG07 CH12 5C076 AA14 BA06 5C077 LL14 PP23 PP65 PP66 PQ08 PQ22 AB05 AB07D07 DE50 GK17 HL11 [Continued Summary] If it does not properly match the linked part, Displaying data items in the dataset is blocked. In the preferred embodiment, a closed linked list is constructed so that parts of the data set can be included in the validation process if desired.

Claims (25)

[Claims] 1. A method of defeating the intent to steal content material, wherein the data is sized sufficiently large to detract from subsequent transmission of the data set over a communication channel of limited bandwidth. Collecting a plurality of data items having content material to form a set, each data item of the data item including one or more parts, thereby forming a plurality of parts including the data set; A plurality of parts to facilitate subsequent detection of the absence of the complete data set based on the absence of the linked part corresponding to the link address of one or more selected parts of the plurality of parts. How to assign a link address to each part of, and the link address is related to other parts of the part. 2. The link address of each part is embedded in that part.
The method of claim 1, encoding as one or more watermarks. 3. One or more watermarks, wherein strong watermark removal is configured to cause corruption of data contained in the portion, and modification of the data contained in the portion. The method of claim 2 having fragile watermarks configured to cause fragile watermark collapse. 4. The method of claim 1, wherein assigning a link address to each portion comprises generating a closed linked list that links the complete portion through the link address of each portion. 5. The method of claim 4, wherein forming the closed linked list includes a random portion. 6. The method of claim 1, wherein assigning a link address to each part comprises selecting a random other part to link to the part via the link address. 7. The method of claim 1, further comprising assigning a confirmation parameter to each portion of the plurality of portions to facilitate subsequent confirmation that each portion corresponding to each link address is a valid portion. The method described in. 8. The method of claim 7, further comprising encoding the link address and confirmation parameter of each part as one or more watermarks embedded in the part. 9. One or more watermarks, wherein strong watermark removal is configured to cause corruption of data contained in the portion, and modification of the data contained in the portion. 9. The method of claim 8 having fragile watermarks configured to cause fragile watermark collapse. 10. A method of decoding content material from a source, the method comprising: reading one or more first integrity parameters associated with a first portion of a data set; One integrity parameter has a link address to a second portion of the dataset, reads one or more second integrity parameters associated with the second portion of the dataset, one or A method of decoding a subsequent portion of a data set depending on further reading of a second integrity parameter. 11. The method of claim 10, wherein the one or more second integrity parameters comprise partial confirmation parameters, and the decoding of subsequent portions is dependent on the partial confirmation parameters. 12. The method of claim 11, wherein the partial confirmation parameter has a random number associated with the second portion when the data set was formed. 13. The method further comprises: reading a subsequent integrity parameter associated with another portion of the dataset based on the reading of the second integrity parameter, the decoding of the subsequent portion of the dataset further including the subsequent integrity parameter. 11. The method of claim 10, which relies on reading the sex parameter. 14. The method of claim 13, further comprising determining when a subsequent read of the integrity parameter has completed reading all portions of the data set. 15. The method of claim 10, further comprising representing content material corresponding to subsequent portions of the dataset. 16. The method of claim 10, wherein the one or more second complete parameters are embedded in the second portion as one or more watermarks. 17. One or more watermarks included in the second portion, and a strong watermark configured such that removal of the strong watermark causes corruption of the data contained in the second portion. 17. The method of claim 16, wherein the modification of the data comprises a fragile watermark configured to cause the fragile watermark to collapse. 18. A storage medium configured to include content material, the storage medium comprising a plurality of parts and one or more complete parameters corresponding to each part of the plurality of parts. And one or more integrity parameters are included to facilitate determining whether a complete plurality of portions is present on a subsequent copy of at least a portion of the plurality of portions. , A storage medium containing a link address that links a corresponding part to another part of a plurality of parts. 19. Selecting a data item having a data set such that the accumulated size of the data set is sufficient to discourage transmission of the data set over a communication channel of limited bandwidth. A data item of each of the data items has one or more parts and is configured to associate a link address with each part of the data item having the data set A binder, the link address corresponds to another part of the data item containing the data set, and one or more other parts of the data item corresponding to the link address of one or more parts of the data set. Depending on the existence of the parts, each part and each associated link address may be used to facilitate the later representation of the data item. A recorder configured to record the stream onto the medium. 20. The encoder of claim 19, wherein the binder is further configured to associate a link address with each portion via random processing. 21. The binder is further configured to associate a partial confirmation parameter with each part, and the recorder further comprises: for facilitating confirmation that the part is present in a subsequent representation of the data item. 20. The encoder of claim 19, configured to record partial confirmation parameters with each part. 22. The encoder of claim 19, wherein the binder assigns partial confirmation parameters to each portion based on random processing. 23. An expression device configured to receive a data item corresponding to a data set and generate a expression corresponding to a selected data item therefrom, each data item of the data item being one or more thereof. Including the above parts, thereby forming a plurality of parts including a dataset, each part of the plurality of parts including a link address corresponding to another part of the dataset, functionally connected to the expressor, Completeness configured to exclude expressions corresponding to selected data items depending on the presence of one or more other parts corresponding to link addresses of one or more parts of the plurality of parts Decoder with checker and. 24. The decoder of claim 23, wherein the integrity checker is further configured to determine the presence of all other parts corresponding to the link addresses of all parts of the plurality of parts. 25. The decoder of claim 23, wherein the integrity checker is further configured to confirm the presence of one or more other parts based on a confirmation parameter associated with each part. .