Blockcipher-based Double-length Hash Functions for Pseudorandom Oracles

Yusuke Naito

Paper 2010/566

Blockcipher-based Double-length Hash Functions for Pseudorandom Oracles

Yusuke Naito

Abstract

The notion of PRO (pseudorandom oracle) is an important security notion of hash functions because a PRO hash function inherits all properties of a random oracle up to the PRO bound (e.g., security against generic attacks, collision resistant security, preimage resistant security and so on). In this paper, we propose a new block cipher-based double-length hash function for PROs. Our hash function uses a single block cipher, which encrypts an $n$ -bit string using a $2 n$ -bit key, and maps an input of arbitrary length to a $2 n$ -bit output. Since many block ciphers supports a -bit key (e.g. AES supports a -bit key), the assumption to use the -bit key length block cipher is acceptable. We prove that our hash function is PRO up to query complexity as long as the block cipher is an ideal cipher. To our knowledge, this is the first time double-length hash function based on a single (practical size) block cipher with the birthday type PRO security.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Published elsewhere. Unknown where it was published
Contact author(s): tolucky tigers @ gmail com
History: 2011-05-11: last of 8 revisions; 2010-11-08: received; See all versions
Short URL: https://ia.cr/2010/566
License: CC BY

BibTeX

@misc{cryptoeprint:2010/566,
      author = {Yusuke Naito},
      title = {Blockcipher-based Double-length Hash Functions for Pseudorandom Oracles},
      howpublished = {Cryptology {ePrint} Archive, Paper 2010/566},
      year = {2010},
      url = {https://eprint.iacr.org/2010/566}
}