def server_to_client(self, server_set, pk, coef_cts):
# Evaluate the polynomial on each element of the server set.
eval_cts = [
poly_eval_horner(coef_cts, e) * int(random(pk['order'])) + e
for e in server_set
]
return eval_cts
def client_to_server(self, client_set, pk, coef_cts):
# Evaluate the polynomial on each element of the client set.
eval_cts = [
poly_eval_horner(coef_cts, e) * random(pk['n']) + e
for e in client_set
]
return eval_cts
def hash(self, pk, sk, message, r=0):
# generate ephemeral trapdoors(p1,q1)
while True:
p1, q1 = randomPrime(pk['secparam']), randomPrime(pk['secparam'])
# print("p1,q1=>",p1,q1)
if isPrime(p1) and isPrime(q1) and p1 != q1:
N1 = p1 * q1
if not gcd(N1, pk['N']) == 1:
continue
break
if r == 0:
r = random(N1 * pk['N'])
# print("r=>",r)
# print("(p1,q1,N1)=>", (p1,q1,N1))
# print("N*N1=>",N1 * pk['N'])
phi_NN1 = pk['phi_N'] * (N1 - p1 - q1 + 1)
# print("phi_NN1=>", phi_NN1)
# find e inverse mod N1 * N, so gcd(e,phi_NN1)==1
while True:
e = random(phi_NN1)
if not gcd(e, phi_NN1) == 1:
continue
break
M = Conversion.bytes2integer(message)
# print("M =>",M)
# to set hash modular N * N1()
group.q = N1 * pk['N']
group.p = group.q * 2 + 1
# print("q=>",group.q)
# print("M hash=>", group.hash(M))
h = (group.hash(M) * (r**e)) % (N1 * pk['N'])
xi = {'h': h, 'r': r, 'N1': N1, 'p1': p1, 'q1': q1, 'e': e}
# print("e=>",xi['e'])
return xi
def client_to_server(self, client_set, pk, coef_cts):
# Evaluate the polynomial on each element of the client set.
eval_cts = [poly_eval_horner(coef_cts, e) * random(pk['n']) + e for e in client_set]
return eval_cts
def encrypt(self, pk, m):
g, n, n2 = pk['g'], pk['n'], pk['n2']
r = random(pk['n'])
c = (((g % n2)**m) * ((r % n2)**n)) % n2
return Cipher(c, pk)
def encrypt(self, pk, m):
g, n, n2 = pk['g'], pk['n'], pk['n2']
r = random(pk['n'])
c = (((g % n2) ** m) * ((r % n2) ** n)) % n2
return Cipher(c, pk)
def server_to_client(self, server_set, pk, coef_cts):
# Evaluate the polynomial on each element of the server set.
eval_cts = [poly_eval_horner(coef_cts, e) * random(pk['n']) + e for e in server_set]
return eval_cts