def hash_chain(pairing_group=None,
start_pg_elem=None,
hops_num=0,
cached_hash_chain_elem={},
to_cache=True):
"""
Compute the pairing group element after the given number of hops using the hash chain by the given starting pairing
group element.
:param pairing_group: pairing group used for the hash chain
:param start_pg_elem: starting pairing group element
:param hops_num: number of hash operations to perform
:return: the resulting pairing group element
"""
res_pg_elem = start_pg_elem
if to_cache:
cached_hash_chain_elem[0] = res_pg_elem
#print('START PG ELEM', res_pg_elem)
if len(cached_hash_chain_elem) > hops_num:
#print('CACHED HASH CHAIN #', hops_num, cached_hash_chain_elem[hops_num])
return cached_hash_chain_elem[hops_num]
# Compute the hash chain hops
for i in range(hops_num):
r = pairing_group.init(ZR,
int(hashPair(res_pg_elem).decode('utf-8'), 16))
#print('R PG ELEM', r)
res_pg_elem = res_pg_elem**r
#print('NEW PG ELEM', res_pg_elem)
if to_cache:
cached_hash_chain_elem[i + 1] = res_pg_elem
return res_pg_elem
def hash_chain(pairing_group=None, start_pg_elem=None, hops_num=0):
"""
Compute the pairing group element after the given number of hops using the hash chain by the given starting pairing
group element.
:param pairing_group: pairing group used for the hash chain
:param start_pg_elem: starting pairing group element
:param hops_num: number of hash operations to perform
:return: the resulting pairing group element
"""
# Compute the hash chain hops
res_pg_elem = start_pg_elem
for i in range(hops_num):
r = pairing_group.init(ZR,
int(hashPair(res_pg_elem).decode('utf-8'), 16))
res_pg_elem = res_pg_elem**r
return res_pg_elem
# fin.write('AA')
# fin.seek(0, 0)
# print(fin.read())
exit(0)
pair_g = pg.pairing_group_create()
# last_elem = pg.random_pairing_group_elem_gen(pair_g)
# max_hops = 100
b = b'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'
el = bytesToObject(b, pair_g)
import re_enc_engine.pairing_group_primitives as eng_pg
r = pair_g.init(ZR, int(hashPair(el).decode('utf-8'), 16))
h_el = el**r
# el = pair_g.random(G2)
# el0 = pair_g.random(G2)
#el0 = eng_pg.hash_chain(pair_g, el, 1)
#print('\n\n')
print(el.type, objectToBytes(el, pair_g))
print(el.type, objectToBytes(r, pair_g))
print(el.type, objectToBytes(h_el, pair_g))
print('\n\n')
el1 = pair_g.init(ZR, value=1)
el2 = pair_g.init(ZR, value=2)
el3 = pair_g.init(ZR, value=4)
el4 = pair_g.init(ZR,
value=int.from_bytes(objectToBytes(el1, pair_g),
'little'))
# ========== MODULE DECRYPTION ========== #
ciphertext['policy'] = '(DEPT1 and TEAM1)'
for k in range(sample_num):
# Their solution
starting = time() * 1000.0
for i in range(iterations):
c = abe.decrypt(ciphertext, pk, sk, pairing_group)
sample_mod_dec += ((time() * 1000.0) - starting)
print('MODULE DEC =', sample_mod_dec / sample_num)
# ========== HASH CHAIN DECRYPTION ========== #
for k in range(sample_num):
# Our solution
starting = time() * 1000.0
cpabe.decrypt(pk, sk, ciphertext)
for j in range(iterations - 1):
r = pairing_group.init(ZR, int(hashPair(pg_elem).decode('utf-8'), 16))
res_pg_elem = pg_elem ** r
sample_hc_dec += ((time() * 1000.0) - starting)
print('HASH CHAIN DEC =', sample_hc_dec / sample_num)
# ========== MODULE HASH CHAIN DECRYPTION ========== #
for k in range(sample_num):
# Our solution
starting = time() * 1000.0
c = abe.decrypt(ciphertext, pk, sk, pairing_group)
d = pg.hash_chain(pairing_group, c, iterations - 1)
sample_mod_hc_dec += ((time() * 1000.0) - starting)
print('MODULE HASH CHAIN DEC =', sample_mod_hc_dec / sample_num)
def hash_p(elem: pairing.pc_element) -> bytes:
sha3 = hashlib.sha3_256()
hashed = hashPair(elem)
sha3.update(hashed)
return sha3.digest()