Systems and methods for authenticating and protecting the integrity of data streams and other data

• US 8,762,711 B2
• Filed: 01/31/2011
• Issued: 06/24/2014
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: PLS IV, LLC (Pretium Partners, LLC)
• Original Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Inventors: Serret-Avila, Xavier
• Primary Examiner(s): BROWN, CHRISTOPHER J
• Application Number:
  US13/018,274
• Publication Number:
  US 20110126084A1
• Time in Patent Office: 1,240 Days
• Field of Search: 713/161, 713/176
• US Class Current: 713/161
• CPC Class Codes: G06F 21/53 by executing in a restricted environment, e.g. sandbox or secure virtual machine
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2149 Restricted operating environment
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

Systems and methods are disclosed for enabling a recipient of a cryptographically-signed electronic communication to verify the authenticity of the communication on-the-fly using a signed chain of check values, the chain being constructed from the original content of the communication, and each check value in the chain being at least partially dependent on the signed root of the chain and a portion of the communication. Fault tolerance can be provided by including error-check values in the communication that enable a decoding device to maintain the chain'"'"'s security in the face of communication errors. In one embodiment, systems and methods are provided for enabling secure quasi-random access to a content file by constructing a hierarchy of hash values from the file, the hierarchy deriving its security in a manner similar to that used by the above-described chain. The hierarchy culminates with a signed hash that can be used to verify the integrity of other hash values in the hierarchy, and these other hash values can, in turn, be used to efficiently verify the authenticity of arbitrary portions of the content file.

Claims

1. A method for encoding and transmitting a digital file in a manner designed to facilitate authentication of a streaming transmission of the digital file, the method being performed by a system comprising a processor and a non-transitory computer-readable storage medium storing instructions that when executed by the processor, cause the processor to perform the method, the method comprising:

generating a progression of check values, each check value in the progression being derived from at least one other check value in the progression and from a portion of the digital file;

encrypting a final check value in the progression of check values, wherein the final check value corresponds to the beginning portion of the digital file;

inserting the encrypted final check value in proximity to the beginning of the streamed transmission of the digital file; and

transmitting the digital file and the progression of check values to a user'"'"'s system, whereby the user'"'"'s system is configured to receive parts of the digital file and to use one or more received check values to authenticate the parts of the digital file before the entire digital file is received.

2. The method of claim 1, wherein the portion of the digital file comprises error-check values, each error-check value being inserted in proximity to a part of the digital file to which said error-check value corresponds, each error-check value being configured to facilitate authentication of a part of the digital file and a check value in the progression of check values.

3. The method of claim 1 further, wherein each error-check value comprises a hash of the part of the digital file to which the error-check value corresponds.

4. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, are configured to cause the processor to perform a method for encoding a data block in a manner designed to facilitate authentication of a streamed transmission of the data block, the method comprising:

generating a progression of data check values, wherein each data check value is derived, at least in part, from at least one other data check value in the progression and a hash of a portion of the data block;

encrypting a final check value in the progression of check values, wherein the final check value corresponds to the beginning portion of the digital file;

inserting the encrypted final check value in proximity to the beginning of the streamed transmission of the digital file; and

encoding the data block by inserting a plurality of error-check values into the data block, each error-check value being inserted in proximity to a part of the data block to which the error-check value corresponds, and each error-check value being operable to facilitate authentication of part of the data block and of a data check value in the progression of data check values.

5. The non-transitory computer-readable storage medium of claim 4, wherein the method further comprises:

sending the streamed transmission of the encoded data block to a user'"'"'s system, the user'"'"'s system being configured to receive and authenticate portions of the streamed transmission before the entire encoded data block is received.

6. The non-transitory computer-readable storage medium of claim 4, wherein the at least one error-check value comprises a hash of the part of the data block to which the error-check value corresponds.

7. The non-transitory computer-readable storage medium of claim 4, wherein the method further comprises:

digitally signing at least a root data check value in the progression of data check values.

8. The non-transitory computer-readable storage medium of claim 4, wherein the computer-readable storage medium is selected from the group consisting of:

CD-ROM, DVD, MINIDISC, floppy disk, magnetic tape, flash memory, ROM, RAM, system memory, hard drive, and optical storage.

9. The non-transitory computer-readable storage medium of claim 4, wherein at least one error-check value comprises a hash of a combination of at least one other error-check value and a hash of a portion of the data block.