• KIPS Transactions on Computer and Communication Systems
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• v.2 no.7
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• pp.311-316
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• 2013

256-bit block cipher XSB(eXtended Spn Block cipher) was proposed in 2012 and has a symmetric strucrure in encryption and decryption process. In this paper, we propose a differential fault analysis on XSB. Based on a random byte fault model, our attack can recover the secret key of XSB by using only two random byte fault injection. This result is the first known cryptanalytic result on the target algorithm.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.3
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• pp.9-17
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• 2012

In this paper, we propose a SPN 256 bit block cipher so called XSB(eXtended SPN Block cipher) which has a symmetric structure in encryption and decryption. The proposed XSB is composed of the even numbers of N rounds where the first half of them, 1 to N/2-1 round, applies a pre-function and the last half of them, N/2+1 to N round, employs a post-function. Each round consists of a round key addition layer, a substiution layer, a byte exchange layer and a diffusion layer. And a symmetry layer is located in between the pre-function layer and the post-function layer. The symmetric layer is composed with a multiple simple bit slice involution S-Boxes. The bit slice involution S-Box symmetric layer increases difficult to attack cipher by Square attack, Boomerang attack, Impossible differentials cryptanalysis etc.