For Full-Text PDF, please login, if you are a member of IEICE,|
or go to Pay Per View on menu list, if you are a nonmember of IEICE.
Generalization and Extension of XEX* Mode
Kazuhiko MINEMATSU Toshiyasu MATSUSHIMA
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/02/01
Online ISSN: 1745-1337
Print ISSN: 0916-8508
Type of Manuscript: PAPER
Category: Cryptography and Information Security
tweakable block cipher, XEX, OCB 2.0,
Full Text: PDF(219.4KB)
>>Buy this Article
This paper describes an extension of XEX* mode, which is a method to convert a block cipher into a tagged tweakable block cipher, a notion introduced by Rogaway in 2004 as an extension of the tweakable block cipher by Liskov et al. Our extension attaches an additional encryption function to the original XEX*, which has some limitation but is slightly faster than the encryption implemented by XEX*. We prove our scheme's security in a general form, where the offset function, a key component of our construction, is not restricted to the one used by XEX*. We also provide some applications of our result, in particular to OCB 2.0, an authenticated encryption based on XEX*.