Uy0wdgG9

1void demo3()
2{
3    vector<double> inputs{0.0,1.1,2.2,3.3,4.4,5.5,6.6,7.7,8.8,9.9};
4
5
6    EncryptionParameters parms(scheme_type::CKKS);
7    size_t poly_modulus_degree = 8192;
8    parms.set_poly_modulus_degree(poly_modulus_degree);
9    parms.set_coeff_modulus(CoeffModulus::Create(poly_modulus_degree, {60, 30, 30, 30, 60}));
10    auto context = SEALContext::Create(parms);
11    double scale = pow(2.0, 30);
12    CKKSEncoder encoder(context);
13
14
15    cout << "Valid parms: " << boolalpha << context->key_context_data()->qualifiers().parameters_set() << endl;
16    cout << "Max allowed coeff_modulus bit-count for this poly_mod_deg: " << CoeffModulus::MaxBitCount(poly_modulus_degree) << endl;
17    cout << "Current coeff_modulus bit-count: " << context->key_context_data()->total_coeff_modulus_bit_count() << endl;
18    cout << "Encoder.slot_count: " << encoder.slot_count() << endl << endl;
19    
20    
21    KeyGenerator keygen(context);
22    auto secret_key = keygen.secret_key();
23    auto public_key = keygen.public_key();
24    auto relin_keys = keygen.relin_keys_local();
25    auto galois_keys = keygen.galois_keys_local();
26    Encryptor encryptor(context, public_key);
27    Decryptor decryptor(context, secret_key);
28
29    Plaintext p;
30    encoder.encode(inputs, scale, p);
31    Ciphertext c;
32    encryptor.encrypt(p, c);
33
34
35//SERVER SIDE
36    Evaluator evaluator(context);
37    auto c_cpy = c;
38
39    for (size_t i = 1; i < encoder.slot_count(); i <<= 1){
40        Ciphertext temp_c;
41        evaluator.rotate_vector(c, i, galois_keys, temp_c);
42        evaluator.add_inplace(c, temp_c);
43    }
44
45    auto N = inputs.size();
46    double N_inv = 1.0;
47    N_inv /= ((int)N);
48    Plaintext pN_inv;
49    encoder.encode(N_inv, scale, pN_inv);
50    Ciphertext c_avg;
51    evaluator.multiply_plain(c, pN_inv, c_avg);
52
53    evaluator.relinearize_inplace(c_avg, relin_keys);
54    evaluator.rescale_to_next_inplace(c_avg);
55    c_avg.scale() = scale;
56    
57
58    c = c_cpy;
59
60    evaluator.mod_switch_to_next_inplace(c);
61    evaluator.sub_inplace(c, c_avg);
62
63    evaluator.square_inplace(c);
64    evaluator.relinearize_inplace(c, relin_keys);
65    evaluator.rescale_to_next_inplace(c);
66    c.scale() = scale;
67
68    auto temp_c = c;
69    for (size_t i = 1; i < inputs.size(); i++){
70        evaluator.rotate_vector_inplace(temp_c, 1, galois_keys);
71        evaluator.add_inplace(c, temp_c);
72    }
73
74    encoder.encode(N_inv, c.parms_id(), scale, pN_inv);
75    Ciphertext c_var;
76    evaluator.multiply_plain(c, pN_inv, c_var);
77
78
79
80
81//CLIENT SIDE
82
83    Plaintext p_avg;
84    decryptor.decrypt(c_avg, p_avg);
85    vector<double> vect;
86    encoder.decode(p_avg, vect);
87    auto avg = vect[0];
88
89    Plaintext p_var;
90    decryptor.decrypt(c_var, p_var);
91    encoder.decode(p_var, vect);
92    auto var = vect[0];
93
94
95    cout << "Average: " << avg << endl;
96    cout << "Variance: " << var << endl;
97}
98