Gimli is a 384-bit permutation function. It can be used in sponge constructions.
GIMLI-Hash
GIMLI-Hash is a simple hash function built on the Gimli permutation.
Test vectors
The test vectors on the Gimli paper are incorrect. The authors have provided corrected values here.
- Input:
""(Empty string) -
Output:
b0634b2c0b082aedc5c0a2fe4ee3adcfc989ec05de6f00addb04b3aaac271f67 - Input:
"There's plenty for the both of us, may the best Dwarf win." - Output:
4afb3ff784c7ad6943d49cf5da79facfa7c4434e1ce44f5dd4b28f91a84d22c8
Useful links
Implementation in Rust
pub(crate) fn gimli(state: &mut [u32; 12]) {
for round in (1..25).rev() {
for col in 0..4 {
let x = state[col].rotate_left(24);
let y = state[col + 4].rotate_left(9);
let z = state[col + 8];
state[col + 8] = x ^ (z << 1) ^ ((y & z) << 2);
state[col + 4] = y ^ x ^ ((x | z) << 1);
state[col] = z ^ y ^ ((x & y) << 3);
}
if (round & 3) == 0 {
// Small swap
state.swap(0, 1);
state.swap(2, 3);
}
if (round & 3) == 2 {
// Big swap
state.swap(0, 2);
state.swap(1, 3);
}
if (round & 3) == 0 {
// Add constant
state[0] ^= 0x9e377900 | round as u32;
}
}
}
