Ascon is a family of cryptographic functions based on a Sponge function / permutation.
The state of Ascon is 5 64-bit values, for a total of 320 bits.
We take a 5-bit S-Box, apply it 64 times across the 5 words, 64 times.
Here is the 5-bit Ascon S-box.
4, 11, 31, 20, 26, 21, 9, 2, 27, 5, 8, 18, 29, 3, 6, 28, 30, 19, 7, 14, 0, 13, 17, 24, 16, 12, 1, 25, 22, 10, 15, 23
We perform a linear “diffusion” 5 times. Each word only affects itself here, but the bits within each word are mixed around.