1. Anonymous Authentication in Group 2001. 9. 11. Course Title: Network Security Faculty : Kwangjo Kim 2001027 Jongseong Kim

2. Network Security 2 1. MOTIVATION ▣ In many parts of crypto applications - internet bidding and auction, electronic voting, lottery, peer to peer communication,.. – an anonymous authentication protocol is needed to keep the identity of members secret. ▣ I will present protocol for authenticating a member in a group which is less computational and faster than existent authentication protocols. ▣ If I finish my work successfully, I’ll get some knowledge about general cryptography, digital signature, hash function, hash chain and so on.

3. Network Security 3 2. REQUIREMENT ▣ Essential requirements Security Anonymity Unlinkablity ▣ Additional requirements Management of membership in group Authentication key management in group

4. Network Security 4 3. OBJECTIVE ▣ Less Computational protocol ▣ Faster than current protocols ▣ Easy to implementation

5. Network Security 5 4. APPROACH ▣ Eliminate flaw of group signature ▣ Minimize using the public-key cryptosystem to achieve proper speed ▣ Apply a hash function and hash chain to managing group members

6. Network Security 6 5.TIME SCHEDULE Time Table Work 3 th 4 th 5 th 6 th 7 th 8 th 9 th 10 th 11 th 12 th 13 th 14 th 15 th Survey related Work Improve protocol mid-term presentation Complete protocols Final report

7. Network Security 7 6. REFERENCES [1] Menezes, “Handbook of Applied Cryptography” [2] Dan Boneh, Matt Franklin. “Anonymous Authentication with subset Queries” Proceedings of the 6th ACM conference on Computer and communications security November 1 - 4, 1999, Singapore [3] Stuart Schechter, Todd Parnell, Alexander Hartemink, “Anonymous authentica- tion of Membership in Dynamic Groups”, Volume 1648, Issue, pp 0184- Lecture Notes in Computer Science [4] David Chaum, Eugene vanHeyst, ”Group Signatures”, Volume 0547, Issue, pp 0257- lecture Notes in Computer Science [5] Michel Abdalla, Sara Miner, Chanathip Namprempre, “Forward-Secure Threshold Signature Schemes”, Volume 2020, Issue, pp 0441- Lecture Notes in Computer Science [6] Michel Abdalla, Sara Miner, Chanathip Namprempre, “Forward-Secure Threshold Signature Schemes”, Volume 2020, Issue, pp 0441-Lecture Notes in Computer Science