For example, running the sequence generator through AES rounds. This is keyed, very fast if the hardware supports it, and permutations of types smaller than the

For example, running the sequence generator through AES rounds. This is keyed, very fast if the hardware supports it, and permutations of types smaller than the block size are collision-free and non-reversible[0] if the AES block is setup suitably. In other cases, a 128-bit key is simply encrypted (conveniently being the same block size as AES), which allows you to put arbitrary structure inside the exported key. [0] http://www.jandrewrogers.com/2019/02/12/fast-perfect-hashing/ http://www.jandrewrogers.com/2019/02/12/fast-perfect-hashing...