Further results on differentially 4-uniform permutations over $\F_{2^{2m}}$
In this paper, we present several new constructions of differentially 4-uniform permutations over $\F_{2^{2m}}$ by modifying the values of the inverse function on some subsets of $\F_{2^{2m}}$. The resulted differentially 4-uniform permutations have high nonlinearities and algebraic degrees, which provide more choices for the design of cryptographic substitution boxes.