Targeted Ciphers for Format-Preserving Encryption


Sarah Miracle and Scott Yilek


We introduce Targeted Ciphers, which typically encipher points on domain X , but can be easily modified to instead encipher points on some subset S of X. Ciphers that can directly support this domain targeting are useful in Format-Preserving Encryption, where one wishes to encipher points on a potentially complex domain S . We propose two targeted ciphers and analyze their security. The first, Targeted Swap-or-Not, is a modification of the Swap-or-Not cipher proposed by Hoang, Morris, and Rogaway (CRYPTO 2012). The second, a new cipher we call Mix-Swap-Unmix, achieves the stronger notion of full security. Our targeted ciphers perform domain targeting more efficiently than the recently proposed Cycle Slicer algorithm of Miracle and Yilek (ASIACRYPT 2017).


Sarah Miracle and Scott Yilek.
Targeted Ciphers for Format-Preserving Encryption
Selected Areas in Cryptography - SAC 2018 LNCS Vol. 11349, pp. 3-26, Springer, 2019.


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SAC 2018