def sim(g, msg, pks, sk, p_id, v_id): a_list = [] r_list = [] h_list = [] for i in range(len(pks)): if i == v_id: a_list.append(None) r_list.append(None) h_list.append(None) else: a_i = Fr() a_i.set_by_CSPRNG() a_list.append(a_i) r_i = g * a_i r_list.append(r_i) h_i = Fr.set_hash_of(f"{msg}{r_i.getStr()}") h_list.append(h_i) a = Fr() a.set_by_CSPRNG() r = (g * a) + reduce( operator.add, [pks[i] * h_list[i].neg() for i in range(len(pks)) if i != v_id]) h = Fr.set_hash_of(f"{msg}{r.getStr()}") s = reduce( operator.add, [a_list[i] + a + (sk * h) for i in range(len(pks)) if i != v_id]) r_list[v_id] = r * sk return (r_list, s)
def keygen(g): sk_p, sk_v = Fr(), Fr() sk_p.set_by_CSPRNG() sk_v.set_by_CSPRNG() pk_p = g * sk_p pk_v = g * sk_v return sk_p, pk_p, sk_v, pk_v
def sign(g, msg, pks, sk, p_id, v_id): a_list = [] r_list = [] h_list = [] for i in range(len(pks)): if i == p_id: a_list.append(None) r_list.append(None) h_list.append(None) else: a_i = Fr() a_i.set_by_CSPRNG() a_list.append(a_i) r_i = g * a_i r_list.append(r_i) h_i = Fr.set_hash_of(f"{msg}{r_i.getStr()}") h_list.append(h_i) a = Fr() a.set_by_CSPRNG() r_list[p_id] = (g * a) + reduce( operator.add, [pks[i] * h_list[i].neg() for i in range(len(pks)) if i != p_id]) h = Fr.set_hash_of(f"{msg}{r_list[p_id].getStr()}") s = reduce( operator.add, [a_list[i] + a + (sk * h) for i in range(len(pks)) if i != p_id]) r_list[v_id] = pks[v_id] * a_list[v_id] g_hat = G2.hashAndMapToG2(f'{msg}{r_list}{pks}') S = g_hat * s return (r_list, S)