التفاصيل البيبلوغرافية
| العنوان: |
Method of managing user key for broadcast encryption |
| Document Number: |
20060129805 |
| تاريخ النشر: |
June 15, 2006 |
| Appl. No: |
11/271989 |
| Application Filed: |
November 14, 2005 |
| مستخلص: |
A user key management method for a broadcast encryption includes assigning node path identifiers (IDs) to nodes arranged in sequence; assigning random seed value keys to the nodes according to the node path IDs; generating key values by repeatedly applying a hash function to the assigned random seed value keys; and assigning the generated key values to the nodes in sequence. Accordingly, it is possible to reduce the transmission overhead that is most important matter in the broadcast encryption to less than the number of the revoked users. Further, there is an advantage that the transmission overhead of the exemplary embodiments of the present invention is remarkably reduced compared with the Subset Difference method. |
| Inventors: |
Kim, Dae-youb (Seoul, KR); Jin, Weon-il (Suwon-si, KR); Kim, Hwan-joon (Seoul, KR); Park, Sung-joon (Seoul, KR); Cheon, Jung-hee (Seoul, KR); Kim, Myung-hwan (Seoul, KR); Jho, Nam-su (Seoul, KR); Yoo, Eun-sun (Namyangju-si, KR) |
| Claim: |
1. A method of managing a user key for a broadcast encryption, the method comprising: assigning node path identifiers (IDs) to nodes which are arranged in sequence; assigning random seed value keys to the nodes according to the node path IDs; generating key values by repeatedly applying a hash function to the assigned random seed value keys; and assigning the generated key values to the nodes in sequence. |
| Claim: |
2. The method of claim 1, wherein an encryption key for an interval formed with N-ary nodes which are arranged in sequence is generated by repeatedly applying the hash function N-1 times to a seed value key which is assigned to a first node in the interval. |
| Claim: |
3. The method of claim 2, wherein the interval is a set of consecutive non-revoked nodes. |
| Claim: |
4. The method of claim 2, wherein the interval includes more than one revoked node and an independent hash function is applied to the revoked node. |
| Claim: |
5. A method of managing a user key for a broadcast encryption, the method comprising: assigning random seed value keys to nodes which are sequentially arranged; generating first key values by repeatedly applying a first hash function to the assigned random seed value keys; assigning the first key values to the nodes in sequence; setting special nodes in a certain interval among the nodes which are sequentially arranged; assigning special seed value keys to the special nodes; generating second key values by repeatedly applying a second hash function to the assigned special seed value keys; and assigning the second key values to the special nodes in sequence. |
| Claim: |
6. The method of claim 5, wherein, when a special node key K is assigned to a first special node of the special nodes, a second key value which is obtained by applying the second hash function to the special node key K is assigned to a second special node located away from the first special node in the certain interval. |
| Claim: |
7. The method of claim 5, wherein an encryption key for an interval formed with N-ary nodes which are arranged in sequence is generated by repeatedly applying the hash function N-1 times to a seed value key which is assigned to a first node in the certain interval. |
| Claim: |
8. The method of claim 7, wherein the certain interval is a set of consecutive non-revoked nodes. |
| Claim: |
9. The method of claim 7, wherein the interval includes more than one revoked node and an independent hash function is applied to the revoked node. |
| Claim: |
10. A method of managing a user key for a broadcast encryption, the method comprising: assigning node path identifiers (IDs) to nodes configured as a circular group; assigning random seed value keys to the nodes according to the node path IDs; generating key values by repeatedly applying a hash function to the assigned random seed value keys; and assigning the generated key values to the nodes in a cyclic way. |
| Claim: |
11. The method of claim 10, wherein an encryption key for a cyclic interval constructed with N-ary nodes in the circular group is generated by repeatedly applying the hash function N-1 times to a seed value key which is assigned to a first node in the interval. |
| Claim: |
12. The method of claim 11, wherein the cyclic interval is a set of consecutive non-revoked nodes. |
| Claim: |
13. The method of claim 10, wherein a layered structure of circular groups is formed by linking nodes configuring a new circular group below each node configuring the circular group. |
| Claim: |
14. The method of claim 13, wherein the layered structure has 16 layers. |
| Claim: |
15. The method of claim 13, wherein a number of nodes in the circular groups is identical. |
| Claim: |
16. The method of claim 10, wherein the cyclic interval formed with the N-ary nodes in the circular group includes more than one revoked node and an independent hash function is applied to the revoked node. |
| Claim: |
17. The method of claim 10, wherein N-ary nodes form the circular group and are assigned the node path IDs from 0 to N-1. |
| Claim: |
18. The method of claim 13, wherein a node having at least one revoked node is regarded as a revoked node in the layered structure. |
| Claim: |
19. A method of managing a user key for a broadcast encryption, the method comprising: assigning random seed value keys to nodes configured as a circular group; generating first key values by repeatedly applying a first hash function to the assigned random seed value keys; assigning the first key values to the nodes in a cyclic way; setting special nodes in a certain interval among the nodes; assigning random special seed value keys to the special nodes; generating second key values by repeatedly applying a second hash function to the assigned random seed value keys; and assigning the second key values to the special nodes in a cyclic way. |
| Claim: |
20. The method of claim 19, wherein, if a special node key K is assigned to a first special node of the special nodes, a second key value which is obtained by applying the second hash function to the special node key K is assigned to a second special node located away from the first special node at the certain interval. |
| Claim: |
21. The method of claim 19, wherein an encryption key for an interval formed with N-ary nodes which are arranged in sequence is generated by repeatedly applying the hash function N-1 times to a seed value key which is assigned to a first node in the interval. |
| Claim: |
22. The method of claim 21, wherein the cyclic interval is a set of consecutive non-revoked nodes. |
| Claim: |
23. The method of claim 21, wherein the cyclic interval includes more than one revoked node and an independent hash function is applied to the revoked node. |
| Current U.S. Class: |
713158/000 |
| Current International Class: |
04 |
| رقم الانضمام: |
edspap.20060129805 |
| قاعدة البيانات: |
USPTO Patent Applications |