Network named fragments in a content centric network

• US 9,832,123 B2
• Filed: 09/11/2015
• Issued: 11/28/2017
• Est. Priority Date: 09/11/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Mosko, Marc E., Wood, Christopher A.
• Primary Examiner(s): CHAN, SAI MING
• Application Number:
  US14/851,894
• Publication Number:
  US 20170078199A1
• Time in Patent Office: 809 Days
• Field of Search: 370392
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 45/306 Route determination based on the nature of the carried application
• CPC Class Codes: H04L 45/7453 using hashing
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 9/00 Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

One embodiment provides a system that facilitates efficient and secure transportation of content. An intermediate node receives a packet that corresponds to a fragment of a content object message that is fragmented into a plurality of fragments. One or more fragments of the plurality of fragments indicate a unique name that is a hierarchically structured variable-length identifier that comprises contiguous name components ordered from a most general level to a most specific level. The received fragment indicates an intermediate state which is based on a hash function performed on an intermediate state from a previous fragment and data included in the received fragment. In response to determining that the received fragment is a first fragment, the system identifies a first entry in a pending interest table for an interest with a name that is based on a hash of a content object and that corresponds to the first fragment.

Claims

1. A computer system for facilitating forwarding of packets, the system comprising:

a processor; and

a storage device storing instructions that, when executed by the processor, cause the processor to perform a method, the method comprising

receiving, by an intermediate node, a packet that corresponds to a fragment of a content object message, wherein the fragment indicates a name that is a hierarchically structured variable-length identifier that comprises contiguous name components ordered from a most general level to a most specific level, and a fragment name for the fragment indicates an intermediate state which is based on a hash function performed at least on an initialization vector; and

in response to determining that the fragment is a first fragment of the content object message, computing a hash of at least the initialization vector to produce a result, and comparing the result with the intermediate state indicated by the fragment.

2. The computer system of claim 1, wherein the fragment name for the fragment indicates a number indicating a byte offset that corresponds to a starting byte for the fragment.

3. The computer system of claim 1, wherein the fragment name for the fragment indicates a digest or a segment identifier for the content object message.

4. The computer system of claim 1, wherein the first fragment indicates a digital signature of a producer of the content object message.

5. The computer system of claim 1, wherein the first fragment includes no payload or a payload with a size smaller than a maximum transmission unit of a network over which the fragment was received.

6. The computer system of claim 1, wherein the fragment indicates a segment identifier that is indicated in other fragments of the content object message and identifies the fragment and the other fragments as corresponding to the content object message.

7. The computer system of claim 6, wherein the fragment is a final fragment of the content object message and includes a digital signature of a producer of the content object message, and the digital signature creates a relationship between the segment identifier and a digest for the content object message.

9. The computer system of claim 1, wherein the method further comprises:

in response to determining that the fragment is the first fragment of the content object message, identifying a first entry in a pending interest table for an interest with a name that is based on a hash of a content object, wherein the intermediate state is based on a hash function performed on data included in the fragment.

10. The computer system of claim 9, wherein the method further comprises:

in response to determining that the fragment is the first fragment;

creating a second entry in the pending interest table based on a digest or a segment identifier for the content object message; and

removing the first entry from the pending interest table; and

in response to determining that the fragment is a subsequent fragment, identifying an entry in the pending interest table for an interest with a digest or a segment identifier that corresponds to the subsequent fragment.

11. The computer system of claim 9, wherein the first fragment includes an overall length for the content object message, a corresponding entry in the pending interest table includes the overall length and a total number of bytes forwarded, and

the method further comprises:

in response to determining that the fragment corresponds to an entry in the pending interest table, updating the total number of bytes forwarded based on a length and a position for the fragment; and

in response to determining that the total number of bytes forwarded is equal to the overall length, removing the corresponding entry from the pending interest table.

8. A computer-implemented method for forwarding packets, the method comprising:

receiving, by an intermediate node, a packet that corresponds to a fragment of a content object message, wherein the fragment indicates a name that is a hierarchically structured variable-length identifier that comprises contiguous name components ordered from a most general level to a most specific level, and a fragment name for the fragment indicates an intermediate state which is based on a hash function performed on an initialization vector; and

in response to determining that the fragment is a first fragment of the content object message, computing a hash of at least the initialization vector to produce a result, and comparing the result with the intermediate state indicated by the fragment.

19. The method of claim 8, the method further comprising:

in response to determining that the fragment is the first fragment, identifying a first entry in a pending interest table for an interest with a name that is based on a hash of a content object, wherein the first fragment includes an overall length for the content object message, and a corresponding entry in the pending interest table includes the overall length and a total number of bytes forwarded,

the method further comprising;

in response to determining that the fragment corresponds to an entry in the pending interest table, updating the total number of bytes forwarded based on a length and a position for the fragment; and

in response to determining that the total number of bytes forwarded is equal to the overall length, removing the corresponding entry from the pending interest table.

20. The method of claim 8, wherein the fragment name for the fragment indicates a number indicating a byte offset that corresponds to a starting byte for the fragment.

21. The method of claim 8, wherein the fragment name for the fragment indicates a digest or a segment identifier for the content object message.

22. The method of claim 8, wherein the first fragment indicates a digital signature of a producer of the content object message.

23. The method of claim 8, wherein the first fragment includes no payload or a payload with a size smaller than a maximum transmission unit of a network over which the fragment was received.

24. The method of claim 8, wherein the fragment indicates a segment identifier that is indicated in other fragments of the content object message and identifies the fragment and the other fragments as corresponding to the content object message.

25. The method of claim 24, wherein the fragment is a final fragment of the content object message and includes a digital signature of a producer of the content object message, and the digital signature creates a relationship between the segment identifier and a digest for the content object message.

26. The method of claim 8, further comprising:

in response to determining that the fragment is the first fragment, identifying a first entry in a pending interest table for an interest with a name that is based on a hash of a content object;

in response to determining that the fragment is the first fragment;

creating a second entry in the pending interest table based on a digest or a segment identifier for the content object message; and

removing the first entry from the pending interest table; and

in response to determining that the fragment is a subsequent fragment, identifying an entry in the pending interest table for an interest with a digest or a segment identifier that corresponds to the subsequent fragment.

12. A computer system for facilitating forwarding of packets, the system comprising:

a processor; and

a storage device storing instructions that, when executed by the processor, cause the processor to perform a method, the method comprising

generating, by a content producing device, a content object message that is responsive to an interest message;

fragmenting the content object message into a plurality of fragments, wherein one or more fragments of the plurality of fragments indicate a name that is a hierarchically structured variable-length identifier that comprises contiguous name components ordered from a most general level to a most specific level;

computing an intermediate state for a first fragment of the one or more fragments based on a hash function performed on an initialization vector for the content object message;

computing an intermediate state for a subsequent fragment of the plurality of fragments based on a hash function performed on an intermediate state from a previous fragment and a payload for the subsequent fragment;

forwarding the first fragment, a fragment name of the first fragment including the intermediate state for the first fragment; and

forwarding the subsequent fragment, the subsequent fragment including the intermediate state for the subsequent fragment.

13. The computer system of claim 12, wherein a fragment name for the one or more fragments indicates a number indicating a byte offset that corresponds to a starting byte for a respective fragment.

14. The computer system of claim 12, wherein the fragment name for the first fragment indicates a digest for the content object message.

15. The computer system of claim 12, wherein the method further comprises:

including in the first fragment a digital signature of the content producing device.

16. The computer system of claim 12, wherein the method further comprises:

including in the first fragment no payload or a payload with a size smaller than a maximum transmission unit of a network over which the first fragment is forwarded.

17. The computer system of claim 12, wherein the method further comprises:

generating a segment identifier for the content object message; and

including the segment identifier in each fragment of the plurality of fragments.

18. The computer system of claim 17, wherein the method further comprises:

in response to determining that the content object message is completely generated, generating a final fragment;

computing a digest for the content object message based on a hash function performed on an intermediate state from a previous fragment and a payload for the final fragment; and

including in the final fragment a digital signature of the content producing device, wherein the digital signature creates a relationship between the segment identifier and the digest for the content object message.