A digital multisignature scheme using bijective public-key cryptosystems
ACM Transactions on Computer Systems (TOCS)
Zero-knowledge proofs of identity
Journal of Cryptology
The knowledge complexity of interactive proof systems
SIAM Journal on Computing
Communication-efficient anonymous group identification
CCS '98 Proceedings of the 5th ACM conference on Computer and communications security
Anonymous authentication with subset queries (extended abstract)
CCS '99 Proceedings of the 6th ACM conference on Computer and communications security
Efficient Identification and Signatures for Smart Cards
CRYPTO '89 Proceedings of the 9th Annual International Cryptology Conference on Advances in Cryptology
Non-Interactive and Information-Theoretic Secure Verifiable Secret Sharing
CRYPTO '91 Proceedings of the 11th Annual International Cryptology Conference on Advances in Cryptology
Wallet Databases with Observers
CRYPTO '92 Proceedings of the 12th Annual International Cryptology Conference on Advances in Cryptology
CRYPTO '98 Proceedings of the 18th Annual International Cryptology Conference on Advances in Cryptology
A Group Signature Scheme with Improved Efficiency
ASIACRYPT '98 Proceedings of the International Conference on the Theory and Applications of Cryptology and Information Security: Advances in Cryptology
Some Open Issues and New Directions in Group Signatures
FC '99 Proceedings of the Third International Conference on Financial Cryptography
Resource-Efficient Anonymous Group Identification
FC '00 Proceedings of the 4th International Conference on Financial Cryptography
A Practical and Provably Secure Coalition-Resistant Group Signature Scheme
CRYPTO '00 Proceedings of the 20th Annual International Cryptology Conference on Advances in Cryptology
On monotone formula closure of SZK
SFCS '94 Proceedings of the 35th Annual Symposium on Foundations of Computer Science
EUROCRYPT'91 Proceedings of the 10th annual international conference on Theory and application of cryptographic techniques
Detecting and Preventing Machine-to-Machine Hijacking Attacks in Cellular Networks
Bell Labs Technical Journal
| Hi-index | 0.00 |
This paper describes two attacks on an anonymous group identification scheme proposed by Handley at Financial Crypto 2000. The first attack enables to forge valid proofs of membership for any secret key. As a consequence, any user, registered or not, can be properly authenticated by the group manager. The second attack enables the authority to recover the identity of any user who authenticates. Those two attacks can be very easily conducted in practice, without any heavy computation. Those attacks can be fixed with simple modifications and additions to the protocolbut we think that the technique used to issue certificates is conceptually flawed and we propose a way to repair this phase of the protocolus ing zero-knowledge proof techniques.