2004 | OriginalPaper | Buchkapitel
Rerandomizable and Replayable Adaptive Chosen Ciphertext Attack Secure Cryptosystems
verfasst von : Jens Groth
Erschienen in: Theory of Cryptography
Verlag: Springer Berlin Heidelberg
Enthalten in: Professional Book Archive
Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.
Wählen Sie Textabschnitte aus um mit Künstlicher Intelligenz passenden Patente zu finden. powered by
Markieren Sie Textabschnitte, um KI-gestützt weitere passende Inhalte zu finden. powered by
Recently Canetti, Krawczyk and Nielsen defined the notion of replayable adaptive chosen ciphertext attack (RCCA) secure encryption. Essentially a cryptosystem that is RCCA secure has full CCA2 security except for the little detail that it may be possible to modify a ciphertext into another ciphertext containing the same plaintext.We investigate the possibility of perfectly replayable RCCA secure encryption. By this, we mean that anybody can convert a ciphertext y with plaintext m into a different ciphertext y′ that is distributed identically to a fresh encryption of m. We propose such a rerandomizable cryptosystem, which is secure against semi-generic adversaries.We also define a weak form of RCCA (WRCCA) security. For this notion we provide a construction (inspired by Cramer and Shoup’s CCA2 secure cryptosystems) that is both rerandomizable and provably WRCCA secure. We use it as a building block in our conjectured RCCA secure cryptosystem.