Recently Budaghyan et al. (Cryptogr. Commun. 12, 85–100, 2020) introduced a procedure for investigating if CCZ-equivalence can be more general than EA-equivalence together with inverse transformation (when applicable). In this paper, we show that it is possible to use this procedure for classifying, up to EA-equivalence, all known APN functions in dimension 6. We also give some discussion for dimension 7, 8 and 9. In particular, in these cases it is possible to give an upper bound on the EA-classes contained in the CCZ-classes of the known APN functions.

中文翻译：

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关于小尺寸已知APN函数的EA类

最近，Budaghyan等人。（Cryptogr。COMMUN。12，85-100，2020年）介绍的程序调查如果CCZ等价可以与逆变换（适用时）比EA-等价更一般在一起。在本文中，我们表明可以使用此过程对维度6中的所有已知APN函数进行分类，直到EA等价。我们还对维度7、8和9进行了一些讨论。特别是在这些情况下可以为已知APN函数的CCZ类中包含的EA类提供上限。