## Cryptology ePrint Archive: Report 2018/124

Evaluating the indistinguishability of the XTS mode in the proposed security model

Nguyen Tuan Anh and Nguyen Bui Cuong

Abstract: In this paper, we consider the indistinguishability of XTS in some security models for both full final block and partial final block cases. Firstly, some evaluations of the indistinguishability up-to-block are presented. Then, we present a new security model in which the adversary can not control sector number, based on an $\epsilon$-collision resistant function. In this model, we give a bound of the distinguishing advantage that the adversary can get when attacks on XTS. The received results is an extension of \cite{6}.

Category / Keywords: secret-key cryptography / block cipher, XTS, indistinguishability, ciphertext stealing