SealPIR/src/main.cpp

#include "pir.hpp"
#include "pir_client.hpp"
#include "pir_server.hpp"
#include <seal/seal.h>
#include <chrono>
#include <memory>
#include <random>
#include <cstdint>
#include <cstddef>

using namespace std::chrono;
using namespace std;
using namespace seal;

int main(int argc, char *argv[]) {

    uint64_t number_of_items = 1 << 12;
    uint64_t size_per_item = 288; // in bytes
    uint32_t N = 4096;

    // Recommended values: (logt, d) = (20, 2).
    uint32_t logt = 20;
    uint32_t d = 2;
    bool use_symmetric = true; // use symmetric encryption instead of public key (recommended)
    bool use_batching = true; // pack as many elements as possible into a BFV plaintext (recommended)

    EncryptionParameters enc_params(scheme_type::bfv);
    PirParams pir_params;

    // Generates all parameters
    
    cout << "Main: Generating SEAL parameters" << endl;
    gen_encryption_params(N, logt, enc_params);
    
    cout << "Main: Verifying SEAL parameters" << endl;
    verify_encryption_params(enc_params);
    cout << "Main: SEAL parameters are good" << endl;

    cout << "Main: Generating PIR parameters" << endl;
    gen_pir_params(number_of_items, size_per_item, d, enc_params, pir_params, use_symmetric, use_batching);
    
    
    print_seal_params(enc_params); 
    print_pir_params(pir_params);


    // Initialize PIR client....
    PIRClient client(enc_params, pir_params);
    cout << "Main: Generating galois keys for client" << endl;

    GaloisKeys galois_keys = client.generate_galois_keys();

    // Initialize PIR Server
    cout << "Main: Initializing server" << endl;
    PIRServer server(enc_params, pir_params);

    // Server maps the galois key to client 0. We only have 1 client,
    // which is why we associate it with 0. If there are multiple PIR
    // clients, you should have each client generate a galois key, 
    // and assign each client an index or id, then call the procedure below.
    server.set_galois_key(0, galois_keys);

    cout << "Main: Creating the database with random data (this may take some time) ..." << endl;

    // Create test database
    auto db(make_unique<uint8_t[]>(number_of_items * size_per_item));

    // Copy of the database. We use this at the end to make sure we retrieved
    // the correct element.
    auto db_copy(make_unique<uint8_t[]>(number_of_items * size_per_item));

    random_device rd;
    for (uint64_t i = 0; i < number_of_items; i++) {
        for (uint64_t j = 0; j < size_per_item; j++) {
            uint8_t val = rd() % 256;
            db.get()[(i * size_per_item) + j] = val;
            db_copy.get()[(i * size_per_item) + j] = val;
        }
    }

    // Measure database setup
    auto time_pre_s = high_resolution_clock::now();
    server.set_database(move(db), number_of_items, size_per_item);
    server.preprocess_database();
    cout << "Main: database pre processed " << endl;
    auto time_pre_e = high_resolution_clock::now();
    auto time_pre_us = duration_cast<microseconds>(time_pre_e - time_pre_s).count();


    // Choose an index of an element in the DB
    uint64_t ele_index = rd() % number_of_items; // element in DB at random position
    uint64_t index = client.get_fv_index(ele_index);   // index of FV plaintext
    uint64_t offset = client.get_fv_offset(ele_index); // offset in FV plaintext
    cout << "Main: element index = " << ele_index << " from [0, " << number_of_items -1 << "]" << endl;
    cout << "Main: FV index = " << index << ", FV offset = " << offset << endl; 

    // Measure query generation
    auto time_query_s = high_resolution_clock::now();
    PirQuery query = client.generate_query(index);
    auto time_query_e = high_resolution_clock::now();
    auto time_query_us = duration_cast<microseconds>(time_query_e - time_query_s).count();
    cout << "Main: query generated" << endl;

    //To marshall query to send over the network, you can use serialize/deserialize:
    //std::string query_ser = serialize_query(query);
    //PirQuery query2 = deserialize_query(d, 1, query_ser, CIPHER_SIZE);

    // Measure query processing (including expansion)
    auto time_server_s = high_resolution_clock::now();
    // Answer PIR query form client 0. If there are multiple clients, 
    // enter the id of the client (to use the associated galois key).
    PirReply reply = server.generate_reply(query, 0); 
    auto time_server_e = high_resolution_clock::now();
    auto time_server_us = duration_cast<microseconds>(time_server_e - time_server_s).count();
    cout << "Main: reply generated" << endl;

    // Measure response extraction
    auto time_decode_s = chrono::high_resolution_clock::now();
    vector<uint8_t> elems = client.decode_reply(reply, offset);
    auto time_decode_e = chrono::high_resolution_clock::now();
    auto time_decode_us = duration_cast<microseconds>(time_decode_e - time_decode_s).count();
    cout << "Main: reply decoded" << endl;

    assert(elems.size() == size_per_item);

    bool failed = false;
    // Check that we retrieved the correct element
    for (uint32_t i = 0; i < size_per_item; i++) {
        if (elems[i] != db_copy.get()[(ele_index * size_per_item) + i]) {
            cout << "Main: elems " << (int)elems[i] << ", db "
                << (int) db_copy.get()[(ele_index * size_per_item) + i] << endl;
            cout << "Main: PIR result wrong at " << i <<  endl;
            failed = true;
        }
    }
    if(failed){
        return -1;
    }

    // Output results
    cout << "Main: PIR result correct!" << endl;
    cout << "Main: PIRServer pre-processing time: " << time_pre_us / 1000 << " ms" << endl;
    cout << "Main: PIRClient query generation time: " << time_query_us / 1000 << " ms" << endl;
    cout << "Main: PIRServer reply generation time: " << time_server_us / 1000 << " ms" << endl;
    cout << "Main: PIRClient answer decode time: " << time_decode_us / 1000 << " ms" << endl;
    cout << "Main: Reply num ciphertexts: " << reply.size() << endl;

    return 0;
}