## CryptoDB

### Paper: Stateful Public-Key Cryptosystems: How to Encrypt with One 160-bit Exponentiation

Authors: Mihir Bellare Tadayoshi Kohno Victor Shoup URL: http://eprint.iacr.org/2006/267 Search ePrint Search Google We show how to significantly speed-up the encryption portion of some public-key cryptosystems by the simple expedient of allowing a sender to maintain state that is re-used across different encryptions. In particular we present stateful versions of the DHIES and Kurosawa-Desmedt schemes that each use only one exponentiation to encrypt, as opposed to two and three respectively in the original schemes, yielding the fastest discrete-log based public-key encryption schemes known in the random-oracle and standard models respectively. The schemes are proven to meet an appropriate extension of the standard definition of IND-CCA security that takes into account novel types of attacks possible in the stateful setting.
##### BibTeX
@misc{eprint-2006-21759,
title={Stateful Public-Key Cryptosystems: How to Encrypt with One 160-bit Exponentiation},
booktitle={IACR Eprint archive},
keywords={public-key cryptography /},
url={http://eprint.iacr.org/2006/267},
note={Preliminary version in ACM CCS 2006. This is the full version. mihir@cs.ucsd.edu 13372 received 12 Aug 2006, last revised 12 Aug 2006},
author={Mihir Bellare and Tadayoshi Kohno and Victor Shoup},
year=2006
}