Tight Lower Bound on Linear Authenticated Encryption

Charanjit S.  Jutla

Paper 2002/132

Tight Lower Bound on Linear Authenticated Encryption

Charanjit S. Jutla

Abstract

We show that any scheme to encrypt m blocks of size n bits while assuring message integrity, that apart from using m+k invocations of random functions (from n bits to n bits) and vn bits of randomness, is linear in (GF2)^n, must have k+v at least Omega(log m). This lower bound is proved in a very general model which rules out many promising linear modes of operations for encryption with message integrity. This lower bound is tight as linear schemes to encrypt m blocks while assuring message integrity by using only m+2+log m invocations are known. of random permutations.

Metadata

Available format(s): PS
Category: Secret-key cryptography
Publication info: Published elsewhere. Unknown where it was published
Keywords: encryption authentication block cipher MAC lower bound
Contact author(s): csjutla @ watson ibm com
History: 2002-08-28: received
Short URL: https://ia.cr/2002/132
License: CC BY

BibTeX

@misc{cryptoeprint:2002/132,
      author = {Charanjit S.  Jutla},
      title = {Tight Lower Bound on Linear Authenticated Encryption},
      howpublished = {Cryptology {ePrint} Archive, Paper 2002/132},
      year = {2002},
      url = {https://eprint.iacr.org/2002/132}
}