Authors:
George Teşeleanu
1
;
2
Affiliations:
1
Advanced Technologies Institute, 10 Dinu Vintilă, Bucharest, Romania
;
2
Simion Stoilow Institute of Mathematics of the Romanian Academy, 21 Calea Grivitei, Bucharest, Romania
Keyword(s):
Mode of Operation, Cipher Block Chaining Mode, Block Cipher, Provable Security.
Abstract:
In this paper we formally introduce a novel mode of operation based on the cipher block chaining mode. The main idea of this mode is to use a stateful block cipher instead of a stateless one. Afterwards, we show how to implement our proposal and present a performance analysis of our mode. Next, we provide a concrete security analysis by computing a tight bound on the success of adversaries based on their resources. The results of our performance and security analyses are that this novel mode is more secure than the cipher block chaining mode for large files, but the encryption/decryption time doubles/triples. Therefore, our novel mode is suitable for encrypting large files, when higher security is required, but speed is not paramount. Note that the changes required to transform the software implementations of the cipher block chaining mode into this new mode are minimal, and therefore transitioning to this new mode is straightforward.