On the Security Notions for Public-Key Encryption Schemes.
Duong Hieu Phan and David Pointcheval.
Abstract:
In this paper, we revisit the security notions for public-key encryption, and
namely indistinguishability. We indeed achieve the surprising result that no decryption
query before receiving the challenge ciphertext can be replaced by queries (whatever
the number is) after having received the challenge, and vice-versa. This remark leads to
a stricter and more complex hierarchy for security notions in the public-key setting: the
(i; j)-IND level, in which an adversary can ask at most i (j resp.) queries before (after
resp.) receiving the challenge. Excepted the trivial implications, all the other relations
are strict gaps, with no polynomial reduction (under the assumption that IND-CCA2
secure encryption schemes exist.) Similarly, we define different levels for non-malleability.
Ref: Proceeding of SCN '04, Lecture Notes in Computer Science Vol. 3352, pages 33-47, Springer-Verlag, 2004.
Available: pdf.