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
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
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
def ballots_as_cipher_collection(self):
"""
Return a MixCipherCollection of the encrypted ballots.
"""
mix_pk = self.mix_pk
mix_nbits = self.mix_nbits
mix_pkfinger = mix_pk.get_fingerprint()
mix_collection = MixCiphertextCollection(mix_pk)
add_ciphertext = mix_collection.add_ciphertext
for v in self.encrypted_ballots:
ballot = v.encrypted_ballot
ct = MixCiphertext(mix_nbits, mix_pkfinger)
ct.append(ballot['a'], ballot['b'])
add_ciphertext(ct)
return mix_collection
def shuffleQuestion(question):
orig = CiphertextCollection(pk)
for ballot in ballots[question]:
ciphertext = Ciphertext(nbits, orig._pk_fingerprint)
for choice in ballot["choices"]:
ciphertext.append(long(choice["alpha"]), long(choice["beta"]))
orig.add_ciphertext(ciphertext)
print("Shuffling answers for question " + str(question))
shuf, proof = orig.shuffle_with_proof()
shufs_list.append(shuf.to_dict())
proofs_list.append(proof.to_dict())
print("Shuffle complete for question " + str(question))
def shuffleQuestion(question):
orig = CiphertextCollection(pk)
for ballot in ballots[question]:
ciphertext = Ciphertext(nbits, orig._pk_fingerprint)
for choice in ballot["choices"]:
ciphertext.append(long(choice["alpha"]), long(choice["beta"]))
orig.add_ciphertext(ciphertext)
print("Shuffling answers for question " + str(question))
shuf, proof = orig.shuffle_with_proof()
shufs_list.append(shuf.to_dict())
proofs_list.append(proof.to_dict())
print("Shuffle complete for question " + str(question))
def ballots_as_cipher_collection(self):
"""
Return a MixCipherCollection of the encrypted ballots.
"""
mix_pk = self.mix_pk
mix_nbits = self.mix_nbits
mix_pkfinger = mix_pk.get_fingerprint()
mix_collection = MixCiphertextCollection(mix_pk)
add_ciphertext = mix_collection.add_ciphertext
for v in self.encrypted_ballots:
ballot = v.encrypted_ballot
ct = MixCiphertext(mix_nbits, mix_pkfinger)
for x in ballot:
ct.append(x['a'], x['b'])
add_ciphertext(ct)
return mix_collection
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
# Trustees
trustees = json.loads(get_file("/trustees"))
trusteeThreshold = int(election['trustee_threshold'])
# Verify mixes
for i in xrange(0, numMixnets):
index = numMixnets - i - 1
for q in xrange(0, numQuestions):
with statusCheck("Verifying mix " + str(index) + " question " + str(q)):
proof = ShufflingProof.from_dict(mixnets[index][1][q], pk, nbits)
orig = CiphertextCollection(pk)
if i == 0:
for ballot in ballots:
ciphertext = Ciphertext(nbits, orig._pk_fingerprint)
for block in ballot["vote"]["answers"][q]["choices"]:
ciphertext.append(long(block["alpha"]), long(block["beta"]))
orig.add_ciphertext(ciphertext)
else:
for ballot in mixnets[index + 1][0][q]["answers"]:
ciphertext = Ciphertext(nbits, orig._pk_fingerprint)
for block in ballot["choices"]:
ciphertext.append(long(block["alpha"]), long(block["beta"]))
orig.add_ciphertext(ciphertext)
shuf = CiphertextCollection(pk)
for ballot in mixnets[index][0][q]["answers"]:
ciphertext = Ciphertext(nbits, shuf._pk_fingerprint)
for block in ballot["choices"]:
ciphertext.append(long(block["alpha"]), long(block["beta"]))
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))]))
threshold_key = setup.generate_private_key(number, secret)
partial_decryptions = []
# Perform partial decryptions
for question in ballots:
partial_decryption_q = []
for ballot in question["answers"]:
ciphertext = Ciphertext(nbits, pkf)
for choice in ballot["choices"]:
ciphertext.append(long(choice["alpha"]), long(choice["beta"]))
partial_decryption = threshold_key.generate_partial_decryption(
ciphertext)
partial_decryption_q.append(partial_decryption)
partial_decryptions.append(partial_decryption_q)
# Convert to Helios format
decryption_factors = [[[str(v.value) for v in decryption]
for decryption in question]
for question in partial_decryptions]
decryption_proofs = [[[{
vote_fingerprint = base64.b64encode(hashlib.sha256(vote_json).digest())[:-1]
if ballot['vote_hash'] != vote_fingerprint:
sc2.fail("Vote fingerprint does not match")
with statusCheck("Verifying mixes") as sc0:
for i in xrange(0, numMixnets):
index = numMixnets - i - 1
with statusCheck("Verifying mix " + str(index), sc0) as sc:
for q in xrange(0, numQuestions):
with statusCheck("Verifying mix " + str(index) + " question " + str(q), sc) as sc2:
proof = ShufflingProof.from_dict(mixnets[index][1][q], pk, nbits)
orig = CiphertextCollection(pk)
if i == 0:
for ballot in ballots:
ciphertext = Ciphertext(nbits, orig._pk_fingerprint)
for block in ballot["vote"]["answers"][q]["choices"]:
ciphertext.append(long(block["alpha"]), long(block["beta"]))
orig.add_ciphertext(ciphertext)
else:
for ballot in mixnets[index + 1][0][q]["answers"]:
ciphertext = Ciphertext(nbits, orig._pk_fingerprint)
for block in ballot["choices"]:
ciphertext.append(long(block["alpha"]), long(block["beta"]))
orig.add_ciphertext(ciphertext)
shuf = CiphertextCollection(pk)
for ballot in mixnets[index][0][q]["answers"]:
ciphertext = Ciphertext(nbits, shuf._pk_fingerprint)
for block in ballot["choices"]:
ciphertext.append(long(block["alpha"]), long(block["beta"]))