def keygen(context, batching): #print("Generating secret/public keys: ") time_start = time.time() keygen = KeyGenerator(context) time_end = time.time() #print("Done in {} miliseconds".format((str)(1000 * (time_end - time_start)))) public_key = keygen.public_key() secret_key = keygen.secret_key() #use moderate size decomposition bit count if batching: gal_keys = GaloisKeys() keygen.generate_galois_keys(30, gal_keys) #since we are going to do some multiplications we are going to relinearize ev_keys = EvaluationKeys() keygen.generate_evaluation_keys(30, ev_keys) return public_key, secret_key, ev_keys, gal_keys else: return public_key, secret_key
print("") parms = EncryptionParameters() parms.set_poly_modulus("1x^4096 + 1") parms.set_coeff_modulus(seal.coeff_modulus_128(4096)) # Note that 40961 is a prime number and 2*4096 divides 40960. parms.set_plain_modulus(40961) context = SEALContext(parms) keygen = KeyGenerator(context) public_key = keygen.public_key() secret_key = keygen.secret_key() gal_keys = GaloisKeys() keygen.generate_galois_keys(30, gal_keys) # Since we are going to do some multiplications we will also relinearize. ev_keys = EvaluationKeys() keygen.generate_evaluation_keys(30, ev_keys) # We also set up an Encryptor, Evaluator, and Decryptor here. encryptor = Encryptor(context, public_key) evaluator = Evaluator(context) decryptor = Decryptor(context, secret_key) # Batching is done through an instance of the PolyCRTBuilder class so need # to start by constructing one. crtbuilder = PolyCRTBuilder(context) slot_count = (int)(crtbuilder.slot_count()) row_size = (int)(slot_count / 2)
def example_batching(): print_example_banner("Example: Batching with PolyCRTBuilder"); parms = EncryptionParameters() parms.set_poly_modulus("1x^4096 + 1") parms.set_coeff_modulus(seal.coeff_modulus_128(4096)) parms.set_plain_modulus(40961) context = SEALContext(parms) print_parameters(context) qualifiers = context.qualifiers() keygen = KeyGenerator(context) public_key = keygen.public_key() secret_key = keygen.secret_key() gal_keys = GaloisKeys() keygen.generate_galois_keys(30, gal_keys) #ev_keys = EvaluationKeys() #keygen.generate_evaluation_keys(30, ev_keys) encryptor = Encryptor(context, public_key) evaluator = Evaluator(context) decryptor = Decryptor(context, secret_key) crtbuilder = PolyCRTBuilder(context) slot_count = (int)(crtbuilder.slot_count()) row_size = (int)(slot_count / 2) print("Plaintext matrix row size: " + (str)(row_size)) def print_matrix(matrix): print("") print_size = 5 current_line = " [" for i in range(print_size): current_line += ((str)(matrix[i]) + ", ") current_line += ("..., ") for i in range(row_size - print_size, row_size): current_line += ((str)(matrix[i])) if i != row_size-1: current_line += ", " else: current_line += "]" print(current_line) current_line = " [" for i in range(row_size, row_size + print_size): current_line += ((str)(matrix[i]) + ", ") current_line += ("..., ") for i in range(2*row_size - print_size, 2*row_size): current_line += ((str)(matrix[i])) if i != 2*row_size-1: current_line += ", " else: current_line += "]" print(current_line) print("") # [ 0, 1, 2, 3, 0, 0, ..., 0 ] # [ 4, 5, 6, 7, 0, 0, ..., 0 ] pod_matrix = [0]*slot_count pod_matrix[0] = 0 pod_matrix[1] = 1 pod_matrix[2] = 2 pod_matrix[3] = 3 pod_matrix[row_size] = 4 pod_matrix[row_size + 1] = 5 pod_matrix[row_size + 2] = 6 pod_matrix[row_size + 3] = 7 print("Input plaintext matrix:") print_matrix(pod_matrix) plain_matrix = Plaintext() crtbuilder.compose(pod_matrix, plain_matrix) encrypted_matrix = Ciphertext() print("Encrypting: ") encryptor.encrypt(plain_matrix, encrypted_matrix) print("Done") print("Noise budget in fresh encryption: " + (str)(decryptor.invariant_noise_budget(encrypted_matrix)) + " bits") pod_matrix2 = [] for i in range(slot_count): pod_matrix2.append((i % 2) + 1) plain_matrix2 = Plaintext() crtbuilder.compose(pod_matrix2, plain_matrix2) print("Second input plaintext matrix:") print_matrix(pod_matrix2) print("Adding and squaring: ") evaluator.add_plain(encrypted_matrix, plain_matrix2) evaluator.square(encrypted_matrix) evaluator.relinearize(encrypted_matrix, ev_keys) print("Done") print("Noise budget in result: " + (str)(decryptor.invariant_noise_budget(encrypted_matrix)) + " bits") plain_result = Plaintext() print("Decrypting result: ") decryptor.decrypt(encrypted_matrix, plain_result) print("Done") crtbuilder.decompose(plain_result) pod_result = [plain_result.coeff_at(i) for i in range(plain_result.coeff_count())] print("Result plaintext matrix:") print_matrix(pod_result) encryptor.encrypt(plain_matrix, encrypted_matrix) print("Unrotated matrix: ") print_matrix(pod_matrix) print("Noise budget in fresh encryption: " + (str)(decryptor.invariant_noise_budget(encrypted_matrix)) + " bits") # Now rotate the rows to the left 3 steps, decrypt, decompose, and print. evaluator.rotate_rows(encrypted_matrix, 3, gal_keys) print("Rotated rows 3 steps left: ") decryptor.decrypt(encrypted_matrix, plain_result) crtbuilder.decompose(plain_result) pod_result = [plain_result.coeff_at(i) for i in range(plain_result.coeff_count())] print_matrix(pod_result) print("Noise budget after rotation" + (str)(decryptor.invariant_noise_budget(encrypted_matrix)) + " bits") # Rotate columns (swap rows), decrypt, decompose, and print. evaluator.rotate_columns(encrypted_matrix, gal_keys) print("Rotated columns: ") decryptor.decrypt(encrypted_matrix, plain_result) crtbuilder.decompose(plain_result) pod_result = [plain_result.coeff_at(i) for i in range(plain_result.coeff_count())] print_matrix(pod_result) print("Noise budget after rotation: " + (str)(decryptor.invariant_noise_budget(encrypted_matrix)) + " bits") # Rotate rows to the right 4 steps, decrypt, decompose, and print. evaluator.rotate_rows(encrypted_matrix, -4, gal_keys) print("Rotated rows 4 steps right: ") decryptor.decrypt(encrypted_matrix, plain_result) crtbuilder.decompose(plain_result) pod_result = [plain_result.coeff_at(i) for i in range(plain_result.coeff_count())] print_matrix(pod_result) print("Noise budget after rotation: " + (str)(decryptor.invariant_noise_budget(encrypted_matrix)) + " bits")