80 lines
2.4 KiB
C++
80 lines
2.4 KiB
C++
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#include <cstddef>
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#include <cstdint>
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#include <iostream>
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#include <vector>
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#include "dpf.hpp"
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#include "dpf/app_flow.hpp"
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#include "dpf/app_plans.hpp"
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// Sabre, the mailbox write with a fast audit (Vadapalli, Storrier, and Henry,
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// S&P 2022). Sender-anonymous messaging: two servers hold subtractive shares
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// of every mailbox and the client sends one key each. Like Express the write
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// is a full-domain add; unlike Express the audit is a *verifiable* DPF proof
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// (Boyle et al. once-per-node fold), a constant-size token per party that
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// opens to accept iff the key is a single honest point.
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//
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// c++ -std=c++17 -march=native -I include -I thirdparty \
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// examples/applications/sabre.cpp
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namespace
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{
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constexpr std::size_t nboxes = 256;
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} // namespace
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int main()
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{
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constexpr std::uint8_t address = 17;
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constexpr std::uint64_t message = 42;
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auto [k0, k1] = dpf::make_dpf(address, message, dpf::verifiable{});
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// Each server folds the write into its mailbox shares (one full walk).
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std::vector<std::uint64_t> box0(nboxes, 0), box1(nboxes, 0);
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dpf::eval_full_add_into(box0, k0);
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dpf::eval_full_add_into(box1, k1);
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if (box0[address] - box1[address] != message)
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{
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std::cerr << "sabre mailbox\n";
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return 1;
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}
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if (box0[0] - box1[0] != 0)
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{
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std::cerr << "sabre neighbor\n";
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return 1;
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}
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// Fast audit: a full-domain VDPF proof. Each party folds a constant-size
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// token; the tokens open to accept an honest single-point write.
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dpf::proof_token pi0{}, pi1{};
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dpf::prove_full(k0, dpf::prove(pi0));
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dpf::prove_full(k1, dpf::prove(pi1));
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if (!dpf::verify(pi0, pi1))
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{
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std::cerr << "sabre audit\n";
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return 1;
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}
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// A proof folded over a mismatched pair of points (the shape a malformed,
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// multi-point write produces) fails the same check.
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dpf::proof_token bad0{}, bad1{};
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dpf::prove_interval(k0, std::uint8_t{0}, std::uint8_t{7}, dpf::prove(bad0));
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dpf::prove_interval(k1, std::uint8_t{8}, std::uint8_t{15}, dpf::prove(bad1));
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if (dpf::verify(bad0, bad1))
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{
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std::cerr << "sabre audit accepted a mismatch\n";
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return 1;
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}
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{
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if (int rc = dpf::app::run_measured("sabre",
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dpf::protocol::mailbox_write_fused_plan(0, 8), 8))
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return rc;
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}
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std::cout << (box0[address] - box1[address]) << "\n";
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return 0;
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}
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