Finding State Collisions in the Authenticated Encryption Stream Cipher ACORN

Md Iftekhar Salam; Kenneth Koon-Ho Wong; Harry Bartlett; Leonie Simpson; Ed Dawson; Josef Pieprzyk

Paper 2015/918

Finding State Collisions in the Authenticated Encryption Stream Cipher ACORN

Md Iftekhar Salam, Kenneth Koon-Ho Wong, Harry Bartlett, Leonie Simpson, Ed Dawson, and Josef Pieprzyk

Abstract

This paper analyzes the authenticated encryption algorithm ACORN, a candidate in the CAESAR cryptographic competition. We identify weaknesses in the state update function of ACORN which result in collisions in the internal state of ACORN. This paper shows that for a given set of key and initialization vector values we can construct two distinct input messages which result in a collision in the ACORN internal state. Using a standard PC the collision can be found almost instantly when the secret key is known.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Preprint.
Keywords: CAESAR Authenticated encryption AEAD ACORN collision stream cipher integrity symmetric encryption message authentication code
Contact author(s): m salam @ qut edu au
History: 2015-09-22: received
Short URL: https://ia.cr/2015/918
License: CC BY

BibTeX

@misc{cryptoeprint:2015/918,
      author = {Md Iftekhar Salam and Kenneth Koon-Ho Wong and Harry Bartlett and Leonie Simpson and Ed Dawson and Josef Pieprzyk},
      title = {Finding State Collisions in the Authenticated Encryption Stream Cipher {ACORN}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/918},
      year = {2015},
      url = {https://eprint.iacr.org/2015/918}
}