Tweakable Block Ciphers

  • Authors:
  • Moses Liskov;Ronald L. Rivest;David Wagner

  • Affiliations:
  • -;-;-

  • Venue:
  • CRYPTO '02 Proceedings of the 22nd Annual International Cryptology Conference on Advances in Cryptology
  • Year:
  • 2002

Quantified Score

Hi-index 0.18

Visualization

Abstract

We propose a new cryptographic primitive, the "tweakable block cipher." Such a cipher has not only the usual inputs - message and cryptographic key - but also a third input, the "tweak." The tweak serves much the same purpose that an initialization vector does for CBC mode or that a nonce does for OCB mode. Our proposal thus brings this feature down to the primitive block-cipher level, instead of incorporating it only at the higher modes-of-operation levels. We suggest that (1) tweakable block ciphers are easy to design, (2) the extra cost of making a block cipher "tweakable" is small, and (3) it is easier to design and prove modes of operation based on tweakable block ciphers.