keccak256-circom/circuits/iota.circom

pragma circom 2.0.0;

include "./utils.circom";

template RC(r) {
    signal output out[64];
    var rc[24] = [
        0x0000000000000001, 0x0000000000008082, 0x800000000000808A,
        0x8000000080008000, 0x000000000000808B, 0x0000000080000001,
        0x8000000080008081, 0x8000000000008009, 0x000000000000008A,
        0x0000000000000088, 0x0000000080008009, 0x000000008000000A,
        0x000000008000808B, 0x800000000000008B, 0x8000000000008089,
        0x8000000000008003, 0x8000000000008002, 0x8000000000000080,
        0x000000000000800A, 0x800000008000000A, 0x8000000080008081,
        0x8000000000008080, 0x0000000080000001, 0x8000000080008008
    ];
    for (var i=0; i<64; i++) {
        out[i] <== (rc[r] >> i) & 1;
    }
}

template Iota(r) {
    signal input in[25*64];
    signal output out[25*64];
    var i;

    component rc = RC(r);

    component iota = XorArray(64);
    for (var i=0; i<64; i++) {
        iota.a[i] <== in[i];
        iota.b[i] <== rc.out[i];
    }
    for (i=0; i<64; i++) {
        out[i] <== iota.out[i];
    }
    for (i=64; i<25*64; i++) {
        out[i] <== in[i];
    }
}