Example #1
0
def test_tiny_circuit():
    t = 2
    n = 5
    c_path = "circuits/tiny_circuit.txt"
    triples = gen_triples(t, n, 2)
    mq = Queue()
    queues = [Queue() for _ in range(n)]
    x = '01'
    y = '10'
    result = '11'
    x_shares = Shamir(t, n).share_bitstring_secret(x)
    y_shares = Shamir(t, n).share_bitstring_secret(y)
    processes = []
    for i in range(n):
        p = Process(target=run_circuit_process,
                    args=(t, n, c_path, i + 1, queues, mq,
                          x_shares[i] + y_shares[i], triples[i]))
        processes.append(p)
    for p in processes:
        p.start()
    vals = []
    while len(vals) < n:
        if not mq.empty():
            vals.append(mq.get())
    reconstructed = Shamir(t, n).reconstruct_bitstring_secret(vals)
    print("result:", reconstructed)
    assert reconstructed == result, "result incorrect"
    print("TEST PASSED")
    for p in processes:
        p.join()
    for q in queues:
        q.close()
        q.join_thread()
    mq.close()
    mq.join_thread()
Example #2
0
 def share_secret(self):
     shaTSS = Shamir(self.t, self.n)
     self.p, alpha = shaTSS.GC(_sage_const_128)
     shares = shaTSS.DS(self.p, alpha, self.members[_sage_const_0].k)
     for i in range(_sage_const_1, self.n + _sage_const_1):
         self.members[i].shares = shares[i - _sage_const_1]
     print('sended shaTSS')
Example #3
0
    def gen_threshold_sign(self, h, m, s, shares):
        shaTSS = Shamir(self.t, self.n)
        k = shaTSS.SC(self.p, shares).list()[_sage_const_0]
        kk = bin(int(str(k)))[_sage_const_2:]
        R = m.parent()
        f_len = int(kk[:_sage_const_8], _sage_const_2)
        fs_len = int(kk[_sage_const_8:_sage_const_16], _sage_const_2)

        R = m.parent()
        f = R([
            -_sage_const_1 * int(x)
            for x in kk[_sage_const_16:_sage_const_16 + f_len]
        ])
        fs = R([
            -_sage_const_1 * int(x)
            for x in kk[_sage_const_16 + f_len:_sage_const_16 + f_len + fs_len]
        ])

        x = auxmath.normilize_coeffs(-(_sage_const_1 / self.q) * m * fs)
        y = auxmath.normilize_coeffs(-(_sage_const_1 / self.q) * m * f)
        s0 = x * f + y * fs
        s_res = R(s + s0)

        b = s_res * auxmath.normilize_coeffs2(s_res * self.h0 - m, self.q)

        print(b)
        print(b.norm(_sage_const_2))
Example #4
0
def test_reconstruction():
	t = 2
	n = 2*t+1
	shamir = Shamir(t, n)
	secret = randelement()
	shares = shamir.share_secret(secret)
	reconstructed = shamir.reconstruct_secret(shares[:t+1])
	assert secret == reconstructed, "reconstructed the wrong value"
Example #5
0
	def share_secret(self):
		self.k = _sage_const_2048 
		self.shaTSS = Shamir(self.t, self.n)
		self.p, alpha = self.shaTSS.GC(self.k)
		print ('k ' + str(self.members[_sage_const_0 ].k))
		shares = self.shaTSS.DS(self.p, alpha, self.members[_sage_const_0 ].k)
		for i in range(_sage_const_1 , self.n+_sage_const_1 ):
			self.members[i].shares = shares[i-_sage_const_1 ]
			self.members[i].alpha = shares[i-_sage_const_1 ][_sage_const_0 ]
		print ('secret generated')
Example #6
0
def gen_triples(t, n, n_triples):
    triples = [[] for _ in range(n)]
    for i in range(n_triples):
        a = randelement()
        b = randelement()
        c = a * b
        a_shares = Shamir(t, n).share_secret(a)
        b_shares = Shamir(t, n).share_secret(b)
        c_shares = Shamir(t, n).share_secret(c)
        for i in range(n):
            triples[i].append(
                TripleShare(a_shares[i], b_shares[i], c_shares[i]))
    return triples
def test_extract_keys():
    k = 7
    secret = 113
    amount_of_keys = 30
    shamir = Shamir(k, secret)
    keys = [shamir.get_key() for _ in range(amount_of_keys)]
    for n in range(1, amount_of_keys + 1):
        key_subset = keys[:n]
        extracted_secret = Shamir.extract_secret(key_subset)
        if n < k:
            # Can get secret... but let's assert anyway
            assert extracted_secret != secret
        else:
            assert extracted_secret == secret
Example #8
0
def test_secure_addition():
	t = 2
	n = 2*t+1
	shamir = Shamir(t, n)
	s1 = randelement()
	s2 = randelement()
	answer = s1+s2
	shares1 = shamir.share_secret(s1)
	shares2 = shamir.share_secret(s2)
	# Each party locally adds their share of secret 1 and 2
	final_shares = [shares1[i]+shares2[i] for i in range(n)]
	# Check
	reconstructed = shamir.reconstruct_secret(final_shares[0:t+1])
	assert answer == reconstructed, "reconstructed the wrong value"
Example #9
0
def consumer(mq, t, n, processes):
    vals = []
    while len(vals) < n:
        if not mq.empty():
            vals.append(mq.get())
    n_triples = len(vals[0])
    for i in [0, 1, n_triples - 2, n_triples - 1]:
        trips = [vals[j][i] for j in range(n)]
        a_shares = [t.a for t in trips]
        b_shares = [t.b for t in trips]
        c_shares = [t.c for t in trips]
        a = Shamir(t, n).reconstruct_secret(a_shares)
        b = Shamir(t, n).reconstruct_secret(b_shares)
        c = Shamir(t, n).reconstruct_secret(c_shares)
        assert a * b == c, "triples are not equal"
Example #10
0
def test_mpc(t, n, c_path, n_triples, inputs, result, reflect=False):
    triples = gen_triples(t, n, n_triples)
    mq = Queue()
    queues = [Queue() for _ in range(n)]
    share_inputs = [Shamir(t, n).share_bitstring_secret(i) for i in inputs]
    processes = []
    for i in range(n):
        inputs = []
        for si in share_inputs:
            inputs.extend(si[i])
        p = Process(target=run_circuit_process, args=(t, n, c_path, i+1, queues, mq, inputs, triples[i]))
        processes.append(p)
    start = time.time()
    for p in processes:
        p.start()
    t1 = Thread(target=consumer, args=(mq, n, result, t, processes, reflect))
    t1.start()
    for p in processes:
        if p.is_alive():
            p.join()
    t1.join(n)
    print(f"time: {round(time.time()-start, 4)} seconds")
    for q in queues:
        q.close()
        q.join_thread()
    mq.join_thread()
Example #11
0
async def eval_circuit(t, n, c, index, queues, main_queue, inputs, triples):
    shamir = Shamir(t, n)
    dispatcher = Dispatcher(t, n, index, queues, "--UNIQUE COMPUTATION ID--")
    outputs = await c.evaluate(inputs,
                               shamir=shamir,
                               dispatcher=dispatcher,
                               triples=triples)
    main_queue.put(outputs)
Example #12
0
def shamir_test(l, m, n):
	s = Shamir('english')
	seed = "Shamir's Secret Sharing Scheme!"[:l] # take first l characters
	shares = s.split(seed, m, n)
	print('original:', seed)
	print('shares:')
	for i in range(len(shares)):
		print('%2d :' % (i + 1), shares[i])
	shares = shares[:m] # take first m shares
	cmb = s.combine(shares)
	print ('combined:', cmb)
	if seed == cmb:
		print('TEST OK')
		print()
	else:
		print('TEST FAILED !!!')
		sys.exit(1)
Example #13
0
def shamir_test(l, m, n):
    s = Shamir('english')
    seed = "Shamir's Secret Sharing Scheme!"[:l]  # take first l characters
    shares = s.split(seed, m, n)
    print('original:', seed)
    print('shares:')
    for i in range(len(shares)):
        print('%2d :' % (i + 1), shares[i])
    shares = shares[:m]  # take first m shares
    cmb = s.combine(shares)
    print('combined:', cmb)
    if seed == cmb:
        print('TEST OK')
        print()
    else:
        print('TEST FAILED !!!')
        sys.exit(1)
Example #14
0
def test_mul32_circuit():
    t = 2
    n = 5
    c_path = "circuits/mul32_circuit.txt"
    triples = gen_triples(t, n, 8000)
    mq = Queue()
    queues = [Queue() for _ in range(n)]
    x = 101
    y = 50000
    result = x * y
    x_bin = bin(x)[2:]
    while len(x_bin) < 32:
        x_bin = '0' + x_bin
    y_bin = bin(y)[2:]
    while len(y_bin) < 32:
        y_bin = '0' + y_bin
    x_shares = Shamir(t, n).share_bitstring_secret(x_bin)
    y_shares = Shamir(t, n).share_bitstring_secret(y_bin)
    processes = []
    for i in range(n):
        p = Process(target=run_circuit_process,
                    args=(t, n, c_path, i + 1, queues, mq,
                          x_shares[i] + y_shares[i], triples[i]))
        processes.append(p)
    for p in processes:
        p.start()
    vals = []
    while len(vals) < n:
        if not mq.empty():
            vals.append(mq.get())
    reconstructed = Shamir(t, n).reconstruct_bitstring_secret(vals)
    print("result:", reconstructed)
    assert eval('0b' + reconstructed) == result, "result incorrect"
    print("TEST PASSED")
    # TO DO: These processes aren't properly closing, so the test stalls here...
    # Probably something to do with some processes being locked/stalled?
    for p in processes:
        p.join()
    for q in queues:
        q.close()
        q.join_thread()
    mq.close()
    mq.join_thread()
Example #15
0
def run_triplegen_process(t, n, index, queues, main_queue, batch_size,
                          n_batches):
    shamir = Shamir(t, n)
    dispatcher = Dispatcher(t, n, index, queues, "")
    tg = TripleGeneration(index,
                          shamir,
                          dispatcher,
                          batch_size=batch_size,
                          n_batches=n_batches)
    tg.run()
    main_queue.put(tg.triples)
Example #16
0
def consumer(mq, n, result, t, processes, reflect):
    vals = []
    while len(vals) < n:
        if not mq.empty():
            vals.append(mq.get())
    reconstructed = Shamir(t, n).reconstruct_bitstring_secret(vals)[::-1]
    if reflect:
        reconstructed = reconstructed[
            int(len(reconstructed) /
                2):] + reconstructed[:int(len(reconstructed) / 2)]
    assert eval('0b' + reconstructed) == eval('0b' +
                                              result), "result incorrect"
Example #17
0
def run_circuit_process(t, n, c_path, index, queues, main_queue, inputs,
                        triples):
    print(f"starting node {index}")
    shamir = Shamir(t, n)
    messenger = MockMessenger(t, n, index, queues)
    c = Circuit(c_path)
    outputs = c.evaluate(inputs,
                         shamir=shamir,
                         messenger=messenger,
                         triples=triples)
    main_queue.put(outputs)
    print(f"closing node {index}")
Example #18
0
 def _testShamir(self, minimum, shares, prime, secret):
     if self.debug >= 10:
         print("testShamir(minimum=%d,shares=%d,prime=%d,secret=%d)" %
               (minimum, shares, prime, secret))
     shamir = Shamir(minimum, prime)
     shamir.setSecret(secret)
     shamir.randomizeKeys(shares, self.rng)
     keys = [shamir.getKey(i) for i in range(1, shares + 1)]
     for t in range(100):
         self._testShamirRecover(minimum, shares, prime, secret, keys)
Example #19
0
def test_mul2_circuit():
    t = 2
    n = 5
    c_path = "bristol_circuits/mul2.txt"
    n_triples = 2
    for x, y in [(0, 1), (0, 0), (1, 1)]:
        result = (x * y)
        result = bin(result)[2:]
        x_bin = bin(x)[2:]
        y_bin = bin(y)[2:]
        inputs = Shamir(t, n).share_bitstring_secret(x_bin + y_bin)
        test_mpc(t, n, c_path, n_triples, inputs, result)
Example #20
0
def test_triple_creation(t, n, n_triples):
    shamir = Shamir(t, n)

    ##
    ## ROUND 1
    ##

    player_ab_lists = [[] for _ in range(n)]
    # Each party
    for _ in range(n):
        # computes random shared values
        ab_lists = shamir.generate_triples_round_1(n_triples)
        # sends each other party their particular shares (point to point)
        for i in range(n):
            player_ab_lists[i].append(ab_lists[i])

    ##
    ## ROUND 2
    ##

    player_a_shares = []
    player_b_shares = []
    player_c_share_shares = [[] for _ in range(n)]
    # Each party
    for i in range(n):
        # collects received ab_list messages and computes intermediate values
        a_shares, b_shares, c_share_shares = shamir.generate_triples_round_2(
            player_ab_lists[i])
        player_a_shares.append(a_shares)
        player_b_shares.append(b_shares)
        # sends each party their c_share_shares (point to point)
        for j in range(n):
            player_c_share_shares[j].append(c_share_shares[j])

    ##
    ## ROUND 3
    ##

    player_triples = []
    # Each party
    for i in range(n):
        # collects received c_share_share messages and computes the result TripleShare values.
        triples = shamir.generate_triples_round_3(player_a_shares[i],
                                                  player_b_shares[i],
                                                  player_c_share_shares[i])
        player_triples.append(triples)

    ## Check
    for i in range(len(player_triples[0])):
        check_a = shamir.reconstruct_secret([p[i].a for p in player_triples])
        check_b = shamir.reconstruct_secret([p[i].b for p in player_triples])
        check_c = shamir.reconstruct_secret([p[i].c for p in player_triples])
        assert check_a * check_b == check_c, "invalid triple was created"
    return player_triples
Example #21
0
	async def operation(self, x, y, uuid):
		bx = bin(x)[2:]
		while len(bx) < 31:
			bx = '0' + bx
		x_shares = Shamir(self.t, self.n).share_bitstring_secret(bx[::-1])
		by = bin(y)[2:]
		while len(by) < 31:
			by = '0' + by	
		y_shares = Shamir(self.t, self.n).share_bitstring_secret(by[::-1])
		tasks = []
		for k, v in self.idx2node.items():
			msg = {'uuid': uuid, 'x_inputs': serialize_shares(x_shares[k-1]), 'y_inputs': serialize_shares(y_shares[k-1])}
			host, port = v
			tasks.append(talk_to_single_server(msg, host, port))
		vals = []
		for res in asyncio.as_completed(tasks, timeout=CLIENT_TIMEOUT):
			msg = await res
			if msg != None:
				vals.append(deserialize_shares(msg['result']))
			if len(vals) > self.t:
				break
		return Shamir(self.t, self.n).reconstruct_bitstring_secret(vals)
Example #22
0
def test_unnormalized_example():
    t = 1
    n = 3
    c_path = "bristol_circuits/unnormalized_subregion_100_10.txt"
    n_triples = 200000
    ones = ['1' for _ in range(1200)]
    inputs = Shamir(t, n).share_bitstring_secret(ones)
    for i in range(len(inputs)):
        inputs[i] = [0 for _ in range(64)] + inputs[i]
    result = bin(300)[2:]
    while len(result) < 64:
        result = '0' + result
    result = result * 10
    test_mpc(t, n, c_path, n_triples, inputs, result)
Example #23
0
def test_add64_circuit():
    t = 2
    n = 5
    c_path = "bristol_circuits/add64.txt"
    n_triples = 500
    for x, y in [(100, 200), (2**30, 2**10), (2**64 - 1, 2**64 - 1)]:
        result = bin((x + y) % (2**64))[2:]
        x_bin = bin(x)[2:]
        while len(x_bin) < 64:
            x_bin = '0' + x_bin
        y_bin = bin(y)[2:]
        while len(y_bin) < 64:
            y_bin = '0' + y_bin
        inputs = Shamir(t, n).share_bitstring_secret(x_bin[::-1] + y_bin[::-1])
        test_mpc(t, n, c_path, n_triples, inputs, result)
Example #24
0
def test_lessthan32_circuit():
    t = 2
    n = 5
    c_path = "bristol_circuits/lessthan32.txt"
    n_triples = 10000
    for x, y in [(111, 2025), (2025, 111), (2**32 - 1, 2**32 - 1)]:
        result = bin(x < y)[2:]
        x_bin = bin(x)[2:]
        while len(x_bin) < 32:
            x_bin = '0' + x_bin
        y_bin = bin(y)[2:]
        while len(y_bin) < 32:
            y_bin = '0' + y_bin
        inputs = Shamir(t, n).share_bitstring_secret(x_bin[::-1] + y_bin[::-1])
        test_mpc(t, n, c_path, n_triples, inputs, result)
Example #25
0
def test_mul64_circuit():
    t = 2
    n = 5
    c_path = "bristol_circuits/mul64.txt"
    n_triples = 10000
    for x, y in [(111, 2025), (2**64 - 1, 2**64 - 1)]:
        result = bin((x * y))[2:]
        x_bin = bin(x)[2:]
        while len(x_bin) < 64:
            x_bin = '0' + x_bin
        y_bin = bin(y)[2:]
        while len(y_bin) < 64:
            y_bin = '0' + y_bin
        inputs = Shamir(t, n).share_bitstring_secret(x_bin[::-1] + y_bin[::-1])
        test_mpc(t, n, c_path, n_triples, inputs, result, reflect=True)
Example #26
0
def test_sub64_circuit():
    t = 2
    n = 5
    c_path = "bristol_circuits/sub64.txt"
    n_triples = 500
    for x, y in [(1000, 2010), (2025, 111), (2**64 - 2, 2**64 - 2)]:
        result = (x - y) % (2**64)
        result = bin(result)[2:]
        x_bin = bin(x)[2:]
        while len(x_bin) < 64:
            x_bin = '0' + x_bin
        y_bin = bin(y)[2:]
        while len(y_bin) < 64:
            y_bin = '0' + y_bin
        inputs = Shamir(t, n).share_bitstring_secret(x_bin[::-1] + y_bin[::-1])
        test_mpc(t, n, c_path, n_triples, inputs, result)
Example #27
0
    def _testShamirRecover(self, minimum, shares, prime, secret, keys):
        if self.debug >= 100:
            print(
                "testShamirRecover(minimum=%d,shares=%d,prime=%d,secret=%s,keys=%s)"
                % (minimum, shares, prime, secret, keys))
        shamir = Shamir(minimum, prime)
        choices = list(range(shares))
        for k in range(minimum):
            i = self.rng.next(len(choices))
            shamir.setKey(choices[i] + 1, keys[choices[i]])
            del choices[i]

        assert shamir.getSecret() == secret
        for i in range(shares):
            assert shamir.getKey(i + 1) == keys[i]
Example #28
0
def test_secure_multiplication():
    t = 2
    n = 2 * t + 1
    n_muls = 5
    shamir = Shamir(t, n)
    xs = [randelement() for _ in range(n_muls)]
    ys = [randelement() for _ in range(n_muls)]
    answers = [xs[i] * ys[i] for i in range(n_muls)]
    x_sharings = [shamir.share_secret(xs[i]) for i in range(n_muls)]
    y_sharings = [shamir.share_secret(ys[i]) for i in range(n_muls)]
    triples = test_triple_creation(t, n, n_muls)

    ##
    ## ROUND 1
    ##

    broadcasts = []
    # Each party
    for i in range(n):
        # computes intermediate values (er_list) for shares to be multiplied
        er_list = shamir.mul_gates_round_1([x[i] for x in x_sharings],
                                           [y[i] for y in y_sharings],
                                           triples[i])
        # broadcasts the intermediate values to all other parties
        broadcasts.append(er_list)

    ##
    ## ROUND 2
    ##

    player_result_shares = []
    # Each party
    for i in range(n):
        # Collects broadcasted messages and uses these intermediate values to compute result shares
        result_shares = shamir.mul_gates_round_2([x[i] for x in x_sharings],
                                                 [y[i] for y in y_sharings],
                                                 broadcasts,
                                                 [t.c for t in triples[i]])
        player_result_shares.append(result_shares)

    # Check values
    for i in range(len(answers)):
        reconstructed = shamir.reconstruct_secret(
            [p[i] for p in player_result_shares])
        assert reconstructed == answers[i], "reconstructed the wrong value"
Example #29
0
class KeySplitter:
    def __init__(self, numshares, threshold):
        self.splitter = Shamir(numshares, threshold)
        self.numshares = numshares
        self.threshold = threshold

    def split(self, key):
        xshares = [''] * self.numshares
        yshares = [''] * self.numshares
        for char in key:
            xcords, ycords = self.splitter.split(ord(char))
            for idx in range(self.numshares):
                xshares[idx] += chr(xcords[idx])
                yshares[idx] += chr(ycords[idx])
        return zip(xshares, yshares)

    def jsonify(self, shares, threshold, split):
        data = {
            'shares': shares,
            'threshold': threshold,
            'split': [base64.b64encode(split[0]),
                      base64.b64encode(split[1])]
        }
        return json.dumps(data)
Example #30
0
class TC_():
    N = _sage_const_251
    NORM_BOUND = _sage_const_321
    q = _sage_const_128
    df = _sage_const_73
    dg = _sage_const_71
    t = _sage_const_2
    n = _sage_const_5
    T = 'transpose'
    p = -_sage_const_1
    H = None
    t_new = None

    members = []
    #users_count = [range(1, n+1)]
    active_users = {}

    def __init__(self):
        for i in range(self.n + _sage_const_1):
            print(i)
            self.add_member()
        self.share_secret()

    def get_free_id(self):
        for i in range(_sage_const_1, self.n + _sage_const_1):
            if i not in self.active_users.values():
                return i
        return -_sage_const_1

    def add_member(self):
        m = Member(self.N, self.q, self.df, self.dg, self.T)
        m.eval_k(self.q)
        self.members.append(m)

    def get_new_member_params(self, username):
        id = self.get_free_id()
        if id == -_sage_const_1:
            print('All clients already connected')
            return pickle.dumps(['server full'])

        f = self.members[id].f
        h = self.members[id].h
        fs = self.members[id].fs
        h0 = self.members[_sage_const_0].h
        shares = self.members[id].shares
        self.active_users.update({username: id})
        print(self.active_users)
        return pickle.dumps([f, fs, h, shares, h0, self.N, self.q])

    def delete_user(self, username):
        del self.active_users[username]

    def share_secret(self):
        self.k = _sage_const_1024
        self.shaTSS = Shamir(self.t, self.n)
        self.p, alpha = self.shaTSS.GC(self.k)
        self.T = self.members[_sage_const_0].T
        print('T: %d' % self.T)
        print('k ' + str(self.members[_sage_const_0].k))
        shares = self.shaTSS.DS(self.p, alpha, self.members[_sage_const_0].k)
        for i in range(_sage_const_1, self.n + _sage_const_1):
            self.members[i].shares = shares[i - _sage_const_1]
        print('secret generated')

    def change_t(self, t_new):
        if t_new > self.n or t_new <= self.t:
            return b'invalid new t'

        sigma_c = _sage_const_2**(-self.n)
        appr = ((self.t + t_new)**(_sage_const_1 / _sage_const_2) *
                _sage_const_2**((self.t + t_new) / _sage_const_2))
        g_cvp = log(appr, _sage_const_2)
        sigma_F = t_new / self.t / self.k * (
            log(sigma_c**(-_sage_const_1 / t_new) * self.n * self.t,
                _sage_const_2) + g_cvp + _sage_const_1)
        alpha_noise = (_sage_const_1 - (_sage_const_1 + sigma_F) /
                       (t_new / self.t))
        H = floor(self.p**alpha_noise / _sage_const_2)
        for i in range(_sage_const_1, self.n + _sage_const_1):
            alpha = self.members[i].shares[_sage_const_0]
            sigma = self.members[i].shares[_sage_const_1]
            self.members[i].shares[_sage_const_1] = self.shaTSS.SG(
                [alpha, sigma], self.p, H)
            #self.members[i].status = ['4', ]
        self.t_new = t_new
        self.H = H
        print(t_new)
        return b'ok'

    def get_info_client(self):
        print(self.active_users)
        return pickle.dumps(
            [self.t, self.n, ', '.join(self.active_users.keys())])
        #return pickle.dumps([self.q, self.members[0].h, self.p, self.t, self.n, self.NN])

    def get_info_dc(self):
        #print ([self.t, self.n, self.q, self.N, self.p, self.members[0].h, self.H, self.t_new])
        return pickle.dumps([
            self.t, self.n, self.N, self.q, self.T, self.p,
            self.members[_sage_const_0].h, self.H, self.t_new
        ])

    def get_user_status(self, username):
        id = self.active_users[username]
        return self.members[id].status

    def set_user_status(self, username, status):
        id = self.active_users[username]
        self.members[id].status = status

    def get_user_shares(self, username):
        id = self.active_users[username]
        return self.members[id].shares

    def gen_partial_sign(self, h, m, s, username):
        id = self.active_users[username]
        user = self.members[id]

        x = Rx(normilize_coeffs(
            -_sage_const_1 / self.q * m * user.fs))._polynomial % self.q
        y = Rx(normilize_coeffs(
            _sage_const_1 / self.q * m * user.f))._polynomial % self.q

        si = (Rx(x * user.f)._polynomial % self.q +
              Rx(y * user.fs)._polynomial % self.q) % self.q
        m = Rx(si * (user.h - h))._polynomial % self.q
        s = s + si
        return user.h, m, s

    def encode_msg(self, D, r):
        return H(D + str(r), self.N, self.q)
Example #31
0
 def __init__(self, numshares, threshold):
     self.splitter = Shamir(numshares, threshold)
     self.numshares = numshares
     self.threshold = threshold