def test_decryption():
g = _default_crypto['generator']
p = _default_crypto['modulus']
q = _default_crypto['order']
texts = [0, 1, 2, 3, 4]
keys = [13, 14, 15, 16]
publics = [pow(g, x, p) for x in keys]
pk = 1
for y in publics:
pk = (pk * y) % p
cts = []
rands = []
for t in texts:
ct = encrypt(t, p, g, q, pk)
cts.append((ct[0], ct[1]))
rands.append(ct[2])
all_factors = []
for x in keys:
factors = compute_decryption_factors(p, g, q, x, cts)
all_factors.append(factors)
master_factors = combine_decryption_factors(p, all_factors)
pts = []
for (alpha, beta), factor in zip(cts, master_factors):
pts.append(decrypt_with_decryptor(p, g, q, beta, factor))
assert pts == texts
cfm = {
'modulus': p,
'generator': g,
'order': q,
'public': pk,
'original_ciphers': cts,
'mixed_ciphers': cts
}
mix1 = mix_ciphers(cfm)
mix = mix_ciphers(mix1)
cts = mix['mixed_ciphers']
all_factors = []
for x in keys:
factors = compute_decryption_factors(p, g, q, x, cts)
all_factors.append(factors)
master_factors = combine_decryption_factors(p, all_factors)
pts = []
for (alpha, beta), factor in zip(cts, master_factors):
pts.append(decrypt_with_decryptor(p, g, q, beta, factor))
assert sorted(pts) == sorted(texts)
def do_decrypt(savefile, outfile, keyfile, nr_parallel):
poll_index = 0
curr_file = savefile + ".0"
with open(keyfile) as f:
key = load(f)
secret = int(key['x'])
pk = key['public_key']
modulus = int(pk['p'])
generator = int(pk['g'])
order = int(pk['q'])
del key
while (os.path.isfile(curr_file)):
curr_outfile = outfile + ".%d" % poll_index
if exists(curr_outfile):
m = "file '%s' already exists, will not overwrite" % (
curr_outfile, )
sys.stderr.write(m + "\n")
poll_index += 1
curr_file = savefile + ".%d" % poll_index
continue
with open(curr_file) as f:
tally = load(f)['tally']
ciphers = [(int(ct['alpha']), int(ct['beta']))
for ct in tally['tally'][0]]
factors = compute_decryption_factors(modulus,
generator,
order,
secret,
ciphers,
nr_parallel=nr_parallel)
decryption_factors = []
factor_append = decryption_factors.append
decryption_proofs = []
proof_append = decryption_proofs.append
for factor, proof in factors:
factor_append(factor)
f = {}
f['commitment'] = {'A': proof[0], 'B': proof[1]}
f['challenge'] = proof[2]
f['response'] = proof[3]
proof_append(f)
factors_and_proofs = {
'decryption_factors': [decryption_factors],
'decryption_proofs': [decryption_proofs]
}
with open(curr_outfile, "w") as f:
dump(factors_and_proofs, f)
poll_index += 1
curr_file = savefile + ".%d" % poll_index
return factors
def do_decrypt(savefile, outfile, keyfile, nr_parallel):
poll_index = 0
curr_file = savefile + ".0"
with open(keyfile) as f:
key = load(f)
secret = int(key['x'])
pk = key['public_key']
modulus = int(pk['p'])
generator = int(pk['g'])
order = int(pk['q'])
public = int(pk['y'])
del key
while(os.path.isfile(curr_file)):
curr_outfile = outfile + ".%d" % poll_index
if exists(curr_outfile):
m = "file '%s' already exists, will not overwrite" % (curr_outfile,)
sys.stderr.write(m + "\n")
poll_index += 1
curr_file = savefile + ".%d" % poll_index
continue
with open(curr_file) as f:
tally = load(f)['tally']
ciphers = [(int(ct['alpha']), int(ct['beta']))
for ct in tally['tally'][0]]
factors = compute_decryption_factors(modulus, generator, order,
secret, ciphers,
nr_parallel=nr_parallel)
decryption_factors = []
factor_append = decryption_factors.append
decryption_proofs = []
proof_append = decryption_proofs.append
for factor, proof in factors:
factor_append(factor)
f = {}
f['commitment'] = {'A': proof[0], 'B': proof[1]}
f['challenge'] = proof[2]
f['response'] = proof[3]
proof_append(f)
factors_and_proofs = {
'decryption_factors': [decryption_factors],
'decryption_proofs': [decryption_proofs]
}
with open(curr_outfile, "w") as f:
dump(factors_and_proofs, f)
poll_index += 1
curr_file = savefile + ".%d" % poll_index
return factors
def do_decrypt(savefile, outfile, keyfile, nr_parallel):
if exists(outfile):
m = "file '%s' already exists, will not overwrite" % (outfile,)
raise ValueError(m)
with open(keyfile) as f:
key = load(f)
secret = int(key['x'])
pk = key['public_key']
modulus = int(pk['p'])
generator = int(pk['g'])
order = int(pk['q'])
public = int(pk['y'])
del key
with open(savefile) as f:
tally = load(f)
ciphers = [(int(ct['alpha']), int(ct['beta']))
for ct in tally['tally'][0]]
factors = compute_decryption_factors(modulus, generator, order,
secret, ciphers,
nr_parallel=nr_parallel)
decryption_factors = []
factor_append = decryption_factors.append
decryption_proofs = []
proof_append = decryption_proofs.append
for factor, proof in factors:
factor_append(factor)
f = {}
f['commitment'] = {'A': proof[0], 'B': proof[1]}
f['challenge'] = proof[2]
f['response'] = proof[3]
proof_append(f)
factors_and_proofs = {
'decryption_factors': [decryption_factors],
'decryption_proofs': [decryption_proofs] }
with open(outfile, "w") as f:
dump(factors_and_proofs, f)
return factors
