International Symposium on Digital Object Identifier: 10.1109/ISIT.2010.5513437 ; Some properties of power permutations, that is, monomials bijective mappings on F2n , are investigated. In particular, the differential spectrum of these functions is shown to be of great interest for estimating their resistance to some variants of differential cryptanalysis. The relationships between the differential spectrum of a power permutation and the weight enumerator of a cyclic code with two zeroes are provided. The functions with a two-valued differential spectrum are also studied and the differential spectra of several infinite families of exponents are computed.