The existence conjecture for recursive APN functions

About 5 years old · traced to

Let n∈Nn\in\mathbb{N} with n≥2n\geq 2. An APN function Fn ⁣:F2n→F2nF_n\colon\mathbb{F}_{2}^n\to\mathbb{F}_{2}^n is recursive if, for each i∈{2,…,n−1}i\in\{2,\dots,n-1\}, there exists an APN function Fi ⁣:F2i→F2iF_i\colon\mathbb{F}_{2}^i\to\mathbb{F}_{2}^i such that

F2≺F3≺⋯≺Fn−1≺Fn.F_2\prec F_3\prec\dots\prec F_{n-1}\prec F_n.

Recursive APN function conjecture. There exists a recursive APN function in every dimension n∈Nn\in\mathbb{N} with n≥2n\geq 2.

The conjecture is motivated by examples of quadratic APN functions in dimension 88 containing APN restrictions successively down to dimension 22, together with the authors' construction of many new APN extensions. Its resolution is not given in the source.

References

Primary source

Christof Beierle, Gregor Leander and Léo Perrin, “Trims and Extensions of Quadratic APN Functions”, arXiv:2108.13280 (2022).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.