منابع مشابه
Tweaking Even-Mansour Ciphers
We study how to construct efficient tweakable block ciphers in the Random Permutation model, where all parties have access to public random permutation oracles. We propose a construction that combines, more efficiently than by mere black-box composition, the CLRW construction (which turns a traditional block cipher into a tweakable block cipher) of Landecker et al. (CRYPTO 2012) and the iterate...
متن کاملMulti-key Analysis of Tweakable Even-Mansour
The tweakable Even-Mansour construction generalizes the conventional Even-Mansour scheme through replacing round keys by strings derived from a master key and a tweak. Besides providing plenty of inherent variability, such a design builds a tweakable block cipher from some lower level primitive. In the present paper, we evaluate the multi-key security of TEM-1, one of the most commonly used one...
متن کاملBalanced permutations Even-Mansour ciphers
The r-rounds Even–Mansour block cipher is a generalization of the well known Even–Mansour block cipher to r iterations. Attacks on this construction were described by Nikolić et al. and Dinur et al. for r = 2, 3. These attacks are only marginally better than brute force but are based on an interesting observation (due to Nikolić et al.): for a “typical” permutation P, the distribution of P(x)⊕ ...
متن کاملBeyond-Birthday-Bound Security for Tweakable Even-Mansour Ciphers with Linear Tweak and Key Mixing
The iterated Even-Mansour construction defines a block cipher from a tuple of public n-bit permutations (P1, . . . , Pr) by alternatively xoring some n-bit round key ki, i = 0, . . . , r, and applying permutation Pi to the state. The tweakable Even-Mansour construction generalizes the conventional Even-Mansour construction by replacing the n-bit round keys by n-bit strings derived from a master...
متن کاملXPX: Generalized Tweakable Even-Mansour with Improved Security Guarantees
We present XPX, a tweakable blockcipher based on a single permutation P . On input of a tweak (t11, t12, t21, t22) ∈ T and a message m, it outputs ciphertext c = P (m⊕∆1)⊕∆2, where ∆1 = t11k⊕t12P (k) and ∆2 = t21k⊕t22P (k). Here, the tweak space T is required to satisfy a certain set of trivial conditions (such as (0, 0, 0, 0) 6∈ T ). We prove that XPX with any such tweak space is a strong twea...
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ژورنال
عنوان ژورنال: IACR Transactions on Symmetric Cryptology
سال: 2020
ISSN: 2519-173X
DOI: 10.46586/tosc.v2020.i4.71-87