libdpf/examples/applications/pir3.cpp

56 lines
1.8 KiB
C++
Raw Permalink Normal View History

#include <cstdint>
#include <iostream>
#include <vector>
#include "dpf.hpp"
#include "dpf/app_flow.hpp"
#include "dpf/app_plans.hpp"
// Three-server index PIR. The database is public and replicated. The
// secret index is one (2,3) point key: each server holds one share and
// dots it with the database. Any two of those dots reconstruct the
// record. This is the library's three-evaluator key (ePrint 2024/1658),
// the same sharing the ledger appends with.
//
// c++ -std=c++17 -march=native -I include -I thirdparty \
// examples/applications/pir3.cpp
int main()
{
constexpr std::size_t n = 256;
constexpr std::uint8_t index = 42;
std::vector<dpf::fp61> database(n);
for (std::size_t i = 0; i < n; ++i)
database[i] = dpf::fp61{static_cast<std::uint64_t>(i * i + 1)};
auto [k1, k2, k3] = dpf::make_dpf3(index, dpf::fp61{1});
const auto s1 = dpf::eval_full_inner_product(k1, database);
const auto s2 = dpf::eval_full_inner_product(k2, database);
const auto s3 = dpf::eval_full_inner_product(k3, database);
const auto opened = dpf::shamir3::reconstruct(
dpf::as_share(k1, s1), dpf::as_share(k2, s2));
const auto opened_13 = dpf::shamir3::reconstruct(
dpf::as_share(k1, s1), dpf::as_share(k3, s3));
if (opened != database[index] || opened_13 != database[index])
{
std::cerr << "pir3\n";
return 1;
}
{
// Client uploads one (2,3) key (two point-key spines) to each server.
constexpr std::size_t depth = 8;
constexpr std::size_t query_bytes = 2 * (16 + depth * 16);
if (int rc = dpf::app::run_measured("pir3",
dpf::protocol::n_server_pir_plan(0, 3, query_bytes,
sizeof(dpf::fp61)),
2))
return rc;
}
std::cout << opened.raw() << "\n";
return 0;
}