Sponges divide state into rate (r) and capacity (c). They "absorb" incoming bytes, perform permutation (moving bits around without losing any of them) on the wh

Sponges divide state into rate (r) and capacity (c). They "absorb" incoming bytes, perform permutation (moving bits around without losing any of them) on the whole state, and "squeeze" out bytes from the rate, while capacity remains hidden. For the secure hash function, the capacity should be at least twice the target, that is for 128-bit security you need 256 bits of capacity. ASCON hash uses 256 bit capacity and 320-256 = 64 bit rate, so to get a 32-byte hash of a 8-byte string (without padding), you'll need to do at least 4 permutations. If you can design a secure permutation that permutes 257 bits, you can make a secure, but impractical hash function from it by setting the rate to 1 bit. For the duplex mode that's used for authenticated encryption, capacity can be lower, because it's keyed -- it's 192 bits in ASCON. This assumes the permutation of the 320-byte state itself is secure, of course.