Key-Privacy in Public-Key Encryption
ASIACRYPT '01 Proceedings of the 7th International Conference on the Theory and Application of Cryptology and Information Security: Advances in Cryptology
CRYPTO '89 Proceedings of the 9th Annual International Cryptology Conference on Advances in Cryptology
Orthogonality between Key Privacy and Data Privacy, Revisited
Information Security and Cryptology
INDOCRYPT '08 Proceedings of the 9th International Conference on Cryptology in India: Progress in Cryptology
New convertible undeniable signature schemes
EUROCRYPT'96 Proceedings of the 15th annual international conference on Theory and application of cryptographic techniques
Confirmer signature schemes secure against adaptive adversaries
EUROCRYPT'00 Proceedings of the 19th international conference on Theory and application of cryptographic techniques
Invisibility and anonymity of undeniable and confirmer signatures
CT-RSA'03 Proceedings of the 2003 RSA conference on The cryptographers' track
New approach for selectively convertible undeniable signature schemes
ASIACRYPT'06 Proceedings of the 12th international conference on Theory and Application of Cryptology and Information Security
Discrete-Log-Based signatures may not be equivalent to discrete log
ASIACRYPT'05 Proceedings of the 11th international conference on Theory and Application of Cryptology and Information Security
Efficient identity-based encryption without random oracles
EUROCRYPT'05 Proceedings of the 24th annual international conference on Theory and Applications of Cryptographic Techniques
A framework for constructing convertible undeniable signatures
ProvSec'10 Proceedings of the 4th international conference on Provable security
Short convertible undeniable signature in the standard model
ISPEC'11 Proceedings of the 7th international conference on Information security practice and experience
Acquiring key privacy from data privacy
Inscrypt'10 Proceedings of the 6th international conference on Information security and cryptology
ACISP'12 Proceedings of the 17th Australasian conference on Information Security and Privacy
Short and efficient convertible undeniable signature schemes without random oracles
Theoretical Computer Science
| Hi-index | 0.00 |
Anonymity or "key privacy" was introduced in [1] as a new security notion a cryptosystem must fulfill, in some settings, in addition to the traditional indistinguishability property. It requires an adversary not be able to distinguish pairs of ciphertexts based on the keys under which they are created. Anonymity for undeniable signatures is defined along the same lines, and is considered a relevant requirement for such signatures. Our results in this paper are twofold. First, we show that anonymity and indistinguishability are not as orthogonal to each other (i.e., independent) as previously believed. In fact, they are equivalent under certain circumstances. Consequently, we confirm the results of [1] on the anonymity of ElGamal's and of Cramer-Shoup's schemes, based on existing work about their indistinguishability. Next, we constructively use anonymous encryption together with secure digital signature schemes to build anonymous convertible undeniable signatures. In this context, we revisit a well known undeniable signature scheme, whose security remained an open problem for over than a decade, and prove that it is not anonymous. Moreover, we repair this scheme so that it provides the anonymity feature and analyze its security in our proposed framework. Finally, we analyze an efficient undeniable signature scheme, which was proposed recently, in our framework; we confirm its security results and show that it also enjoys the selective conversion feature.