BFC = (long(proof["commitment"]["B"]) * pow(factor, C, P)) % P
if AT != BFC:
raise VerificationException("alpha^t != B(factor)^c (mod p)")
decryption_factor_combination *= factor
# Check the claimed decryption
decryption_factor_combination *= result[block]
if (decryption_factor_combination % P) != (long(ballot["choices"][block]["beta"]) % P):
print("FAIL")
raise VerificationException("Claimed plaintext doesn't match decryption factors")
else:
# We need a ThresholdPublicKey
tesu = ThresholdEncryptionSetUp(cryptosystem, len(trustees), trusteeThreshold)
for trustee in xrange(0, len(trustees)):
commitment = trustees[trustee]['commitment']
def to_ciphertext(idx):
ciphertext = Ciphertext(nbits, trustees[idx]['public_key_hash'])
for i in xrange(0, len(commitment['encrypted_partial_private_keys'][idx])):
ciphertext.append(long(commitment['encrypted_partial_private_keys'][idx][i]['alpha']), long(commitment['encrypted_partial_private_keys'][idx][i]['beta']))
return ciphertext
tesu.add_trustee_commitment(trustee, ThresholdEncryptionCommitment(
cryptosystem, len(trustees), trusteeThreshold,
[long(x) for x in commitment['public_coefficients']],
[to_ciphertext(x) for x in xrange(0, len(commitment['encrypted_partial_private_keys']))]
trusteesIn = sys.argv[2]
with open(electionIn, 'r') as electionFile:
election = json.load(electionFile)
with open(trusteesIn, 'r') as trusteesFile:
trustees = json.load(trusteesFile)
nbits = ((int(math.log(long(trustees[0]["public_key"]["p"]), 2)) - 1)
& ~255) + 256
cryptosystem = EGCryptoSystem.load(
nbits, long(trustees[0]["public_key"]["p"]),
int(trustees[0]["public_key"]
["g"])) # The generator might be a long if it's big? I don't know.
setup = ThresholdEncryptionSetUp(cryptosystem, len(trustees),
election["trustee_threshold"])
# Add trustee public keys
for i in xrange(0, len(trustees)):
pk = PublicKey(cryptosystem, long(trustees[i]["public_key"]["y"]))
setup.add_trustee_public_key(i, pk)
commitment = setup.generate_commitment()
print(
json.dumps({
"public_coefficients":
[str(x) for x in commitment.public_coefficients],
"encrypted_partial_private_keys": [
# The partial private key is too big for one single (a, b) pair
[{
if election["public_key"] is not None: nbits = ((int(math.log(long(election["public_key"]["p"]), 2)) - 1) & ~255) + 256 cryptosystem = EGCryptoSystem.load(nbits, long(election["public_key"]["p"]), int(election["public_key"]["g"])) # The generator might be a long if it's big? I don't know. public_key = PublicKey(cryptosystem, long(election["public_key"]["y"])) pkf = public_key.get_fingerprint() else: nbits = ((int(math.log(long(trustees[0]["public_key"]["p"]), 2)) - 1) & ~255) + 256 cryptosystem = EGCryptoSystem.load(nbits, long(trustees[0]["public_key"]["p"]), int(trustees[0]["public_key"]["g"])) with open(secretIn, 'r') as secretFile: secret_json = json.load(secretFile) secret = PrivateKey(cryptosystem, long(secret_json["x"])) setup = ThresholdEncryptionSetUp(cryptosystem, len(trustees), election["trustee_threshold"]) # Add trustee commitments for trustee in xrange(0, len(trustees)): def to_ciphertext(idx): ciphertext = Ciphertext(nbits, PublicKey(cryptosystem, long(trustees[idx]["public_key"]["y"])).get_fingerprint()) for i in xrange(0, len(trustees[trustee]["commitment"]["encrypted_partial_private_keys"][idx])): ciphertext.append(long(trustees[trustee]["commitment"]["encrypted_partial_private_keys"][idx][i]["alpha"]), long(trustees[trustee]["commitment"]["encrypted_partial_private_keys"][idx][i]["beta"])) return ciphertext setup.add_trustee_commitment(trustee, ThresholdEncryptionCommitment( cryptosystem, len(trustees), election["trustee_threshold"], [long(x) for x in trustees[trustee]["commitment"]["public_coefficients"]], [to_ciphertext(idx) for idx in range(0, len(trustees))]
public_key = PublicKey(cryptosystem, long(election["public_key"]["y"]))
pkf = public_key.get_fingerprint()
else:
nbits = ((int(math.log(long(trustees[0]["public_key"]["p"]), 2)) - 1)
& ~255) + 256
cryptosystem = EGCryptoSystem.load(nbits,
long(trustees[0]["public_key"]["p"]),
int(trustees[0]["public_key"]["g"]))
with open(secretIn, 'r') as secretFile:
secret_json = json.load(secretFile)
secret = PrivateKey(cryptosystem, long(secret_json["x"]))
setup = ThresholdEncryptionSetUp(cryptosystem, len(trustees),
election["trustee_threshold"])
# Add trustee commitments
for trustee in xrange(0, len(trustees)):
def to_ciphertext(idx):
ciphertext = Ciphertext(
nbits,
PublicKey(cryptosystem, long(
trustees[idx]["public_key"]["y"])).get_fingerprint())
for i in xrange(
0,
len(trustees[trustee]["commitment"]
["encrypted_partial_private_keys"][idx])):
ciphertext.append(
import json, math, sys
electionIn = sys.argv[1]
trusteesIn = sys.argv[2]
with open(electionIn, 'r') as electionFile:
election = json.load(electionFile)
with open(trusteesIn, 'r') as trusteesFile:
trustees = json.load(trusteesFile)
nbits = ((int(math.log(long(trustees[0]["public_key"]["p"]), 2)) - 1) & ~255) + 256
cryptosystem = EGCryptoSystem.load(nbits, long(trustees[0]["public_key"]["p"]), int(trustees[0]["public_key"]["g"])) # The generator might be a long if it's big? I don't know.
setup = ThresholdEncryptionSetUp(cryptosystem, len(trustees), election["trustee_threshold"])
# Add trustee public keys
for i in xrange(0, len(trustees)):
pk = PublicKey(cryptosystem, long(trustees[i]["public_key"]["y"]))
setup.add_trustee_public_key(i, pk)
commitment = setup.generate_commitment()
print(json.dumps({
"public_coefficients": [str(x) for x in commitment.public_coefficients],
"encrypted_partial_private_keys": [
# The partial private key is too big for one single (a, b) pair
[{"alpha": str(x.gamma[i]), "beta": str(x.delta[i])} for i in xrange(0, x.get_length())]
for x in commitment.encrypted_partial_private_keys
]
AT = pow(long(ballot["choices"][block]["alpha"]), T, P)
BFC = (long(proof["commitment"]["B"]) * pow(factor, C, P)) % P
if AT != BFC:
sc4.fail("alpha^t != B(factor)^c (mod p)")
decryption_factor_combination *= factor
# Check the claimed decryption
decryption_factor_combination *= result[block]
if (decryption_factor_combination % P) != (long(ballot["choices"][block]["beta"]) % P):
sc3.fail("Claimed plaintext doesn't match decryption factors")
else:
# We need a ThresholdPublicKey
tesu = ThresholdEncryptionSetUp(cryptosystem, len(trustees), trusteeThreshold)
for trustee in xrange(0, len(trustees)):
commitment = trustees[trustee]['commitment']
def to_ciphertext(idx):
ciphertext = Ciphertext(nbits, trustees[idx]['public_key_hash'])
for i in xrange(0, len(commitment['encrypted_partial_private_keys'][idx])):
ciphertext.append(long(commitment['encrypted_partial_private_keys'][idx][i]['alpha']), long(commitment['encrypted_partial_private_keys'][idx][i]['beta']))
return ciphertext
tesu.add_trustee_commitment(trustee, ThresholdEncryptionCommitment(
cryptosystem, len(trustees), trusteeThreshold,
[long(x) for x in commitment['public_coefficients']],
[to_ciphertext(x) for x in xrange(0, len(commitment['encrypted_partial_private_keys']))]
