A power APN function CCZ-equivalent to Kasami function in even dimension

Abstract

Let $n$ be an even number such that $n\equiv 0(\mathrm{mod}4)$. We show that a power function $x^d$, with $d=2^{\frac{n+2}{2}}+2^{\frac{n-2}{2}}-1$, on ${\mathbb{F}}_{2^n}$ is an APN function of degree $n/2$ which is CCZ-equivalent to Kasami functions of degrees $n/2$ and $(n+4)/2$.

My colleagues have identified some technical errors which require redress