darkfi/doc/spend.pseudo

param secret
param serial
param coin_merkle_branch[4]
param coin_merkle_is_right[4]
constant generator_coin
constant generator_value_commit_value
constant generator_value_commit_random

public nullifier = mimc_hash(secret, serial)

private (public_u, public_v) = jj_mul(secret, generator_coin)
public coin = mimc_hash(public_u, public_v, value, serial, randomness_coin)

let current = coin
for i in range(4):
    branch = coin_merkle_branch[i]
    is_right = coin_merkle_is_right[i]

    # reverse(a, b, condition) = if condition (b, a) else (a, b)
    private left, right = conditionally_reverse(current, branch, is_right)

    # Only the last one is public
    if i == 3:
        current = public mimc_hash(left, right)
    else:
        current = private mimc_hash(left, right)

private value_digits = unpack(value)
rangeproof_assert(value, value_digits)
public value_commit = jj_add(
    jj_mul(value, generator_value_commit_value),
    jj_mul(randomness_value, generator_value_commit_random)
)