def verify(sig, msg):
global secret, E, l, P, sP
# a = e_l(P, secret * Q) = e_l(P, Q) ^ secret
a = symmetric_tate_pairing(E, P, sig, l)
# Q = MapToPoint(m')
# b = e_l(secret * P, Q) = e_l(P, Q) ^ secret
h = int(hashlib.sha512(msg).hexdigest(), 16)
b = symmetric_tate_pairing(E, sP, MapToPoint(E, E.field(h)), l)
# a = b?
return a == b
def encrypt(E, P, sP, pubkey, m, l):
assert isinstance(m, (int, long))
# r = rand()
r = random.randint(2**30, 2**31)
# r*P, m xor e_l(secret * P, Q)^r = e_l(P, Q) ^ (secret * r)
return (r * P,
m ^ H(E.field(symmetric_tate_pairing(E, sP, pubkey, l) ** r)))
def check_time_key(self, Q, HT):
"""
時刻サーバが配信するsH(T)が正しいものか確認する
Args:
Q: sH(T)
HT: HT
"""
# left = e(Q,P) = e(sH(T), P)
# print("tt=", T)
left = self.H(
self.E.field(symmetric_tate_pairing(self.E, Q, self.P, self.l)))
# right = e(H(T),sP)
right = self.H(
self.E.field(symmetric_tate_pairing(self.E, HT, self.sP, self.l)))
if left == right:
print("Time key is correct")
else:
print("[NOTE] Time key is not correct !")
def decrypt(sHT0, C):
"""
時刻サーバが配信してきたsHT0を用いて
暗号文Cを復号化
Args:
sHT0:時刻鍵 (整数)
C:(Enc(m), rP)
"""
sT0 = H(E.field(symmetric_tate_pairing(E, sHT0, C[1], l)))
return C[0] ^ sT0
def decrypt_2(self, sHT0, Enc, rP):
"""
時刻サーバが配信してきたsHT0を用いて
暗号文Cを復号化
Args:
Enc: 暗号文 string
rP : E上の点 string
"""
# rP = rP.decode("base64").decode("zlib")
# rP = dill.loads(rP)
#e(sH(T0), rP)
sT0 = self.H(
self.E.field(symmetric_tate_pairing(self.E, sHT0, rP, self.l)))
return Enc ^ sT0
def decrypt(self, sHT0, C):
"""
時刻サーバが配信してきたsHT0を用いて
暗号文Cを復号化
Args:
sHT0:時刻鍵 (整数)
C:(Enc(m), rP)
"""
#e(sH(T0), rP)
try:
sT0 = self.H(
self.E.field(symmetric_tate_pairing(self.E, sHT0, C[1],
self.l)))
except:
print("Error!")
return C[0] ^ sT0
def encrypt(self, m, T0):
"""
1.時刻を整数に変換
2.その整数を楕円曲線上の点に変換
3.その点を用いて暗号化鍵sT0をペアリング計算
4.sT0で暗号化
Args:
T0:復号時刻 string
m:平文 string
"""
# r = 2
r = random.randint(2**30, 2**31)
# T0 = int(hashlib.sha512(T0).hexdigest().encode("hex"), 16) # 時刻を整数に
T0 = (hashlib.sha512(T0.encode()).hexdigest())
T0 = binascii.hexlify(T0.encode())
T0 = int(T0, 16)
T0 = self.time_to_ecc(T0) # 時刻からEに変換
sT0 = self.H(
self.E.field(
symmetric_tate_pairing(self.E, T0, r * self.sP,
self.l))) # ペアリング計算
return (sT0 ^ m, r * self.P) # (整数, 楕円曲線上の点(射影座標表示))
def encrypt(m, T0):
"""
1.時刻を整数に変換
2.その整数を楕円曲線上の点に変換
3.その点を用いて暗号化鍵sT0をペアリング計算
4.sT0で暗号化
Args:
T0:復号時刻 string
m:平文 string
"""
r = 2
# r = random.randint(2**30, 2**31)
# 時刻を整数に
T0 = (hashlib.sha512(T0.encode()).hexdigest())
T0 = binascii.hexlify(T0.encode())
T0 = int(T0, 16)
# 時刻からEに変換
T0 = time_to_ecc(T0)
# print("type T0", type(T0))
print("---------------------------\n", E, "\n", T0, "\n", r * secret * P, "\n", l, "\n")
print("l =", l)
# ペアリング計算
sT0 = H(E.field(symmetric_tate_pairing(E, T0, r * secret * P, l)))
return (sT0 ^ m, r * P) # (整数, 楕円曲線上の点(射影座標表示))
def decrypt(E, K, c, l):
# c1, c2 = r*P, m xor e_l(secret * P, Q) ^ r = e_l(P, Q) ^ (secret * r)
# a = e_l(c1, K) = e_l(r*P, secret * Q) = e_l(P, Q) ^ (secret * r)
print symmetric_tate_pairing(E, c[0], K, l)
return c[1] ^ H(E.field(symmetric_tate_pairing(E, c[0], K, l)))
def encrypt(E, P, sP, pubkey, m, l):
assert isinstance(m, (int, long))
# r = rand()
r = random.randint(2**30, 2**31)
# r*P, m xor e_l(secret * P, Q)^r = e_l(P, Q) ^ (secret * r)
return (r * P, m ^ H(E.field(symmetric_tate_pairing(E, sP, pubkey, l)**r)))
def decrypt(E, K, c, l): # c1, c2 = r*P, m xor e_l(secret * P, Q) ^ r = e_l(P, Q) ^ (secret * r) # a = e_l(c1, K) = e_l(r*P, secret * Q) = e_l(P, Q) ^ (secret * r) return c[1] ^ H(E.field(symmetric_tate_pairing(E, c[0], K, l)))