Permutation polynomials in several variables over residue class rings
Hans Kaiser, W. Nöbauer · Journal of the Australian Mathematical Society Series A Pure Mathematics and Statistics · 1987
Abstract The concept of a permutation polynomial function over a commutative ring with 1 can be generalized to multiplace functions in two different ways, yielding the notion of a k-ary permutation polynomial function (k > 1, k ∈ N) and the notion of a strict k-ary permutation polynomial function respectively. It is shown that in the case of a residue class ring Zm of the integers these two notions coincide if and only if m is squarefree.