基于可逆Hash函数的DES型超伪随机置换的新构造

On the Construction of Super-Pseudorandom DES-Model Permutations Based on the Reversible Hash Functions

为优化Luby和Rackoff给出的DES型置换的构造,给出4-轮DES型超伪随机置换的构造Ψ(h,f,f,h-1),指出首末两轮双对称ε-△-通用可逆Hash函数和中间两轮DES-型随机置换的组合构造是超伪随机置换.构造降低了对首末轮函数的要求,提高了DES型超伪随机置换在运算和密钥使用方面的效率.

Towards making the construction method on the DES-model pseudorandom permutations given by Luby and Rackoff optimal and practical, a 4-round DES-model pseudorandom permutations ψ（h,f,f,h^-1） is provided. It reduced the complexity of construction and showing that two DES-model permutations is sufficient to be superpseudorandom permutation together with initial and final reversible Hash functions. The revised construction is efficient in terms of computations and key material used and reduces the requirement of the first and fourth round functions.