def test_shamir_recombine_threshold3_shares4(self):
field = ZpField(37)
V = field.value_type
recombiner = SecretRecombiner(field)
# 4 shares OK: secret is recovered
secret = recombiner.recombine([(V(2), V(35)), (V(7), V(30)), (V(5), V(20)), (V(4), V(34))], x_recomb=V(0))
self.assertEquals(secret, V(12))
def test_shamir_recombine_threshold3_shares3(self):
field = ZpField(37)
V = field.value_type
recombiner = SecretRecombiner(field)
# 3 shares NOK: random result
secret = recombiner.recombine([(V(2), V(35)), (V(4), V(34)), (V(5), V(20))], x_recomb=V(0))
self.assertEquals(secret, V(0))
def test_shamir_share_private_key(self):
ssl_add_system_seeds()
k = KEY()
k.generate()
pkey_bignum = k.get_privkey_bignum()
pubkey = k.get_pubkey()
numshares = 600
threshold = 100
sharenum_bytes = 2
print "private_key_bignum:", pkey_bignum
print "public_key:", hexstr(pubkey)
print "address:", BitcoinAddress.from_publickey(pubkey, MAIN)
field = ZpField()
V = field.value_type
ZpPkey = V(pkey_bignum)
sharer = SecretSharer(field, ZpRandom(field))
shares = sharer.share(ZpPkey, threshold, [V(i+1) for i in range(numshares)])
# print shares
print "Shamir Shares: (%d/%d):" % (threshold, numshares)
shares_hex = [hexstr(base256encode(int(pt), sharenum_bytes) + base256encode(int(value), 32)) for pt, value in shares]
for share in shares_hex:
print share
# Try to reconstruct the private key using the hex encoded shares.
recombiner = SecretRecombiner(field)
for i in range(10):
random4_hex = random.sample(shares_hex, threshold)
random4_decoded = [decodehexstr(h) for h in random4_hex]
random4 = [(V(base256decode(data[:sharenum_bytes])), V(base256decode(data[sharenum_bytes:]))) for data in random4_decoded]
recombined_pkey_bignum = recombiner.recombine(random4, V(0))
assert recombined_pkey_bignum == ZpPkey
k2 = KEY()
k2.set_privkey_bignum(int(recombined_pkey_bignum))
assert k2.get_pubkey() == pubkey
print i
# With threshold-1 shares this fails
for i in range(10):
random4_hex = random.sample(shares_hex, threshold-1)
random4_decoded = [decodehexstr(h) for h in random4_hex]
random4 = [(V(base256decode(data[:sharenum_bytes])), V(base256decode(data[sharenum_bytes:]))) for data in random4_decoded]
recombined_pkey_bignum = recombiner.recombine(random4, V(0))
assert recombined_pkey_bignum != ZpPkey