Source identification for unauthorized copies of content

• US 8,739,308 B1
• Filed: 03/27/2012
• Issued: 05/27/2014
• Est. Priority Date: 03/27/2012
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Roth, Gregory B., Barbour, Marc R., Behm, Bradley Jeffery, Ilac, Cristian M., Brandwine, Eric Jason
• Primary Examiner(s): Okeke, Izunna
• Application Number:
  US13/431,898
• Time in Patent Office: 791 Days
• Field of Search: None
• US Class Current: 726/32
• CPC Class Codes: G06F 21/1078 Logging; Metering
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: H04L 2209/24 Key scheduling, i.e. generating round keys or sub-keys for block encryption
• CPC Class Codes: H04L 9/0819 Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) network architectures or network communication protocols for key distribution in a packet data network H04L63/062
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees
• CPC Class Codes: H04N 21/44055 by partially decrypting, e.g. decrypting a video stream that has been partially encrypted
• CPC Class Codes: H04N 21/4627 Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08

Abstract

Systems and methods for authentication generate keys from secret credentials shared between authenticating parties and authenticators. Generation of the keys may involve utilizing specialized information in the form of parameters that are used to specialize keys. Keys and/or information derived from keys held by multiple authorities may be used to generate other keys such that signatures requiring such keys and/or information can be verified without access to the keys. Keys may also be derived to form a hierarchy of keys that are distributed such that a key holder'"'"'s ability to decrypt data depends on the key'"'"'s position in the hierarchy relative to the position of a key used to encrypt the data. Key hierarchies may also be used to distribute key sets to content processing devices to enable the devices to decrypt content such that sources or potential sources of unauthorized content are identifiable from the decrypted content.

Claims

1. A computer-implemented method for identifying sources of unauthorized copies of content, comprising:

under the control of one or more computer systems configured with executable instructions,

obtaining a copy of content comprising a plurality of records, each record having a decrypted portion of original content that comprises a plurality of original records where;

each of the plurality of records corresponds to an original record;

a subset of the original records consists of records that each has multiple copies of a portion of the original content that varies among the multiple copies; and

for each record having multiple copies of a corresponding portion of the original content, at least two of the copies are encrypted by different keys at least one of which is part of a key hierarchy used to distribute keys to content processing devices, the key hierarchy comprising a root key and a plurality of subordinate keys;

selecting, from the plurality of records, records that each correspond to a respective original record of the subset of the original records;

generating a key set by at least matching each selected record to a key used to decrypt a corresponding portion of original content to obtain the corresponding decrypted portion of the original content, the generated key set including a particular key that is a subordinate key of the key hierarchy;

matching the generated key set to a set of the content processing devices by at least identifying a set of devices having access to all of the keys in the generated key set, access to the particular key being based at least in part on access to a key between the particular key and the root key on a key path connecting the particular key to the root key; and

providing one or more electronic records that collectively identify at least a subset of the set of the content processing devices.

2. The computer-implemented method of claim 1, wherein:

the key hierarchy comprises a plurality of hierarchical levels including a root level that includes the root key, each non-root hierarchical level comprising one or more of the subordinate keys; and

each subordinate key is derived based at least in part on a key from a higher hierarchical level.

3. The computer-implemented method of claim 2, wherein each subordinate key is:

derivable based at least in part on any key that is both on a key path connecting the subordinate key to the root key and higher in the key hierarchy than the subordinate key; and

underivable from any subordinate key lower than the subordinate key in the key hierarchy.

4. The computer-implemented method of claim 1, wherein matching the generated key set to a set of the content processing devices includes accessing a data store that associates content processing devices with keys to which the content processing devices have access.

5. The computer-implemented method of claim 1, wherein:

for a particular record of the subset that corresponds to a particular original record comprising multiple copies of a corresponding portion of the original content, the corresponding portion of the original content varies in a manner satisfying one or more criteria for one or more differences among the multiple copies being humanly imperceptible but computationally distinguishable; and

wherein selecting records includes computationally distinguishing differences among the multiple copies.

6. A computer-implemented method for identifying a source of data, comprising:

under the control of one or more computer systems configured with executable instructions,

identifying, based at least in part on the data, a key set comprising one or more keys used to decrypt original data to obtain the data, the identified key set comprising one or more keys from a multi-level key hierarchy, the multi-level key hierarchy comprising a root key and a plurality of subordinate keys and the identified key set including a particular key that is a subordinate key of the key hierarchy;

identifying, based at least in part on the identified key set, one or more devices that are different from other devices at least as a result of having access to the particular key by having access to a key between the particular key and the root key on a key path connecting the particular key to the root key; and

providing information identifying the identified one or more devices.

7. The computer-implemented method of claim 6, wherein:

the one or more devices and the other devices form a set of devices that each have access to a corresponding key set of a plurality of key sets;

for each key set of the plurality of key sets, the key set comprises one or more keys of the multi-level key hierarchy; and

the multi-level hierarchy level comprises a plurality of levels, the plurality of levels comprising a top level and one or more subordinate levels below the top level in the key hierarchy, each subordinate level of the plurality of levels comprising one or more keys derived at least in part on one or more keys of a higher level.

8. The computer-implemented method of claim 6, wherein:

the identified one or more devices have access to the particular key; and

one or more of the other devices have access to a derived key generated based at least in part on the particular key but lack access to the particular key.

9. The computer-implemented method of claim 6, wherein:

the identified key set includes multiple keys;

for one or more of the keys in the key set, devices having access to the one or more keys in the key set form a superset of the identified one or more devices that includes at least one device that lacks at least one key from the identified key set; and

identifying the one or more devices includes determining the one or more devices in a manner that excludes any device from the superset that lacks the at least one key.

10. The computer-implemented method of claim 6, wherein the data comprises content encoded for processing by a multimedia processing device.

11. The computer-implemented method of claim 6, wherein:

the original data includes multiple encrypted copies of a data set;

the multiple encrypted copies include a first copy decryptable using a first key and a second copy decryptable using a second key different from the first key;

the first copy and the second copy, when decrypted, differ between themselves; and

identifying the key set includes identifying a copy from the multiple copies included in the data and determining a key used to decrypt the identified copy.

13. The system of claim 6, wherein:

the one or more devices and the other devices form a set of devices that each have access to a corresponding key set of a plurality of key sets;

for each key set of the plurality of key sets, the key set comprises one or more keys of the multi-level key hierarchy; and

the multi-level hierarchy level comprises a plurality of levels, the plurality of levels comprising a top level and one or more subordinate levels below the top level in the key hierarchy, each subordinate level of the plurality of levels comprising one or more keys derived at least in part on one or more keys of a higher level.

14. The system of claim 6, wherein:

the identified one or more devices have access to the particular key; and

one or more of the other devices have access to a derived key generated based at least in part on the particular key but lack access to the particular key.

15. The system of claim 6, wherein:

the identified key set includes multiple keys;

for one or more of the keys in the key set, devices having access to the one or more keys in the key set form a superset of the identified one or more devices that includes at least one device that lacks at least one key from the identified key set; and

identifying the one or more devices includes determining the one or more devices in a manner that excludes any device from the superset that lacks the at least one key.

16. The system of claim 6, wherein the data comprises content encoded for processing by a multimedia processing device.

17. The system of claim 6, wherein:

the original data includes multiple encrypted copies of a data set;

the multiple encrypted copies include a first copy decryptable using a first key and a second copy decryptable using a second key different from the first key;

the first copy and the second copy, when decrypted, differ between themselves; and

identifying the key set includes identifying a copy from the multiple copies included in the data and determining a key used to decrypt the identified copy.

18. The system of claim 6, wherein, for each first subordinate key of the plurality of subordinate keys:

the first subordinate key is derived based at least in part on output of a function calculated based at least in part on another subordinate key of the plurality of subordinate keys; and

the first subordinate key has a first position in the multi-level key hierarchy relative to a second position of the other subordinate key as a result of having been derived based at least in part on the other subordinate key.

12. A system, comprising:

one or more processors; and

memory including instructions that, when executed by the one or more processors, cause the system to;

identify, based at least in part on data, a key set comprising one or more keys used to decrypt original data to obtain the data, the identified key set comprising one or more keys from a multi-level key hierarchy, the multi-level key hierarchy comprising a root key and a plurality of subordinate keys and the identified key set including a particular key that is a subordinate key of the key hierarchy;

identify, based at least in part on the identified key set, one or more devices that are different from other devices at least as a result of having access to the particular key by having access to a key between the particular key and the root key on a key path connecting the particular key to the root key; and

provide information identifying the identified one or more devices.

19. A non-transitory computer-readable storage medium having stored thereon instructions that, when executed by one or more processors of a computer system, cause the computer system to:

identify, based at least in part on data, a key set comprising one or more keys used to decrypt original data to obtain the data, the identified key set comprising one or more keys from a multi-level key hierarchy, the multi-level key hierarchy comprising a root key and a plurality of subordinate keys and the identified key set including a particular key that is a subordinate key of the key hierarchy;

identify, based at least in part on the identified key set, one or more devices that are different from other devices at least as a result of having access to the particular key by having access to a key between the particular key and the root key on a key path connecting the particular key to the root key; and

provide information identifying the identified one or more devices.

20. The non-transitory computer-readable storage medium of claim 19, wherein:

the one or more devices and the other devices form a set of devices that each have access to a corresponding key set of a plurality of key sets;

for each key set of the plurality of key sets, the key set comprises one or more keys of the multi-level key hierarchy; and

the multi-level hierarchy level comprises a plurality of levels, the plurality of levels comprising a top level and one or more subordinate levels below the top level in the key hierarchy, each subordinate level of the plurality of levels comprising one or more keys derived at least in part on one or more keys of a higher level.

21. The non-transitory computer-readable storage medium of claim 19, wherein:

the identified one or more devices have access to the particular key; and

one or more of the other devices have access to a derived key generated based at least in part on the particular key but lack access to the particular key.

22. The non-transitory computer-readable storage medium of claim 19, wherein:

the identified key set includes multiple keys;

for one or more of the keys in the key set, devices having access to the one or more keys in the key set form a superset of the identified one or more devices that includes at least one device that lacks at least one key from the identified key set; and

the instructions that, when executed by the one or more processors, cause the computer system to identify the one or more devices include instructions that, when executed by the one or more processors, cause the computer system to determine the one or more devices in a manner that excludes any device from the superset that lacks the at least one key.

23. The non-transitory computer-readable storage medium of claim 19, wherein the data comprises content encoded for processing by a multimedia processing device.

24. The non-transitory computer-readable storage medium of claim 19, wherein:

the original data includes multiple encrypted copies of a data set;

the multiple encrypted copies include a first copy decryptable using a first key and a second copy decryptable using a second key different from the first key;

the first copy and the second copy, when decrypted, differ between themselves; and

identifying the key set includes identifying a copy from the multiple copies included in the data and determining a key used to decrypt the identified copy.