Validation system and verification method including signature device and verification device to verify contents

Patent metadata

Field	Value
Publication number	US-9021266-B2
Application number	US-201113267130-A
Country	US
Kind code	B2
Filing date	Oct 6, 2011
Priority date	Nov 17, 2010
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

Provided are methods and a validation system that includes a signature device and a verification device for verifying a content. The signature device may generate verification information for each segment of a divided content and may generate signature information to verify the integrity of each segment and whether a corresponding segment is a part of a content. When a segment is received, the verification device may verify integrity of the segment and whether the segment is a part of the content, based on the verification information and the signature value received from the signature device.

First claim

What is claimed is:

1. A signature device of a validation system, the signature device comprising:
a processor comprising:
a dividing unit to divide content into a plurality of segments;
a hash unit to calculate an initial hash value by hashing the content before the content is divided and to calculate a hash value of each of the plurality of segments;
a content hash generating unit to generate a content hash value by performing an exclusive or (XOR) operation with respect to the hash values of the plurality of segments and the initial hash value;
a signature unit to sign the content hash value with a signature key to generate a signature value;
a verification information generating unit to generate verification information for each of the segments by performing an XOR operation with respect to the content hash value with each of the hash values of the plurality of segments; and
a packet generating unit to generate a packet for each of the plurality of segments, each packet including a corresponding segment, verification information associated with the corresponding segment, and the signature value.

2. The signature device of claim 1 , wherein the packet generating unit is further configured to generate the packet for each of the plurality of segments based on the following equation:
si ∥(hi XOR h) ∥sign(h),

where si corresponds to an i the segment, hi corresponds to the hash value of the i th segment, h corresponds to the content hash value, and sign(h) corresponds to the signature value obtained by signing the content hash value with the signature key.

3. A verification device of a validation system, the signature device comprising:
a processor comprising:
a receiving unit to receive a packet including a segment, verification information associated with the segment, and a signature value;
a hash unit to calculate a hash value of the segment by hashing the segment;
a content hash determining unit to determine a content hash value by performing an XOR operation with respect to the hash value of the segment and the verification information associated with the segment; and
a verifying unit to verify the packet by comparing the content hash value with a verification value that is obtained by decoding the signature value with a public key,
wherein the verification information is obtained by performing an XOR operation with respect to hash value of a plurality of segments that are included in content, an initial hash value by hashing the content, and a hash value of the received segment.

4. The signature device of claim 3 , wherein the verifying unit is further configured to verify an integrity of each of the segments and whether each segment is a part of the content based on the verification information and the signature value received from the signature device.

5. The signature device of claim 3 , wherein, in response to the content hash value being the same as the verification value, the verifying unit verifies that the segment is a part of the content and that the segment has integrity.

6. The signature device of claim 3 , wherein the content hash value is obtained by performing an XOR operation with respect to hash values of a plurality of segments that are included in content.

7. The signature device of claim 3 , wherein the content hash value is obtained by further performing an XOR operation with respect to hash values of a plurality of segments included in content and an initial hash value that is obtained by hashing the content.

8. A signature device of a validation system, the signature device comprising:
a processor comprising:
a dividing unit to divide content into a plurality of segments;
a hash unit to calculate an initial hash value by hashing the content before the content is divided and to calculate a hash value of each of the plurality of segments;
a content hash generating unit to generate a content hash value based on the hash values of the plurality of segments and the initial hash value;
a signature unit to sign the content hash value with a signature key to generate a signature value; and
a verification information generating unit to generate verification information including the hash values of the plurality of segments and the signature value.

9. The signature device of claim 8 , wherein the content hash generating unit performs one of:
hashing again using the hash values of the plurality of segments as a factor of a hash function to generate the content hash value;
connecting and hashing of the hash values of the plurality of segments to generate the content hash value; and
an XOR operation with respect to the hash values of the plurality of segments to generate the content hash value.

10. The signature device of claim 8 , wherein:
the content hash generating unit performs one of:
hashing again using the hash values of the plurality of segments and the initial hash value as a factor of a hash function to generate the content hash value;
connecting and hashing of the hash values of the plurality of segments and the initial hash value to generate the content hash value; and
an XOR operation with respect to the hash values of the plurality of segments and the initial hash value to generate the content hash value.

11. The signature device of claim 10 , wherein the verification information generating unit generates the verification information by further including the initial value.

12. The signature device of claim 8 , further comprising:
a transmitting unit to transmit metadata including the verification information, and to transmit a packet including a segment.

13. A verification device of a validation system, the verification device comprising:
a processor comprising:
a receiving unit to receive metadata including verification information and a segment;
a content hash generating unit to generate a content hash value based on hash values of a plurality of segments, wherein the hash values are included in the verification information; and
a verifying unit to verify whether the verification information has integrity by comparing the content hash value with a verification value that is obtained by decoding a signature value included in the verification information with a public key, and, in response to the verification information having integrity, to verify the received segment based on the hash values that are included in the verification information,
wherein the verification information is obtained by performing an XOR operation with respect to hash value of a plurality of segments that are included in content, an initial hash value by hashing the content, and a hash value of the received segment.

14. The verification device of claim 13 , wherein the verifying unit verifies that the verification information has integrity if the verification value is the same as the content hash value.

15. The verification device of claim 13 , wherein, in response to the verification information having integrity, and a hash value of the received segment being the same as a hash value of a corresponding segment included in the verification information, the verifying unit verifies that the received segment is a part of content and that the received segment has integrity.

16. A method of performing a signature for verifying content in a signature device by a processor, the method comprising:
dividing content into a plurality of segments;
calculating an initial hash value by hashing the content before the content is divided and to calculate a hash value of each of the plurality of segments;
generating a content hash value by performing an exclusive

Assignees

• Kim Dae Youb
• Samsung Electronics Ltd

Inventors

• Kim Dae Youb

Classifications

• H04L9/0643

  Hash functions, e.g. MD5, SHA, HMAC or f9 MAC · CPC title

• H04L2209/60

  Digital content management, e.g. content distribution · CPC title

• H04L9/3247

  involving digital signatures · CPC title

• H04L9/3242 Primary

  involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC · CPC title