Add tfhe-rs parameter alignment, PBS comparison benchmark, CI, and Apptainer

nindanaoto · claude · nindanaoto · commit 2d91bb04af66 · 2026-03-02T15:48:29.000Z
- include/params/tfhe-rs.hpp: update parameters to match tfhe-rs
  DEFAULT_PARAMETERS (boolean, 132-bit security):
    lvl0: n=805, α=5.86e-6 (binary keys)
    lvl1: k=3, N=512, l=2, Bgbit=10, binary keys, α=9.32e-10
    lvl10param: t=5, basebit=3
    lvl2: k=2, N=1024, l=2, Bgbit=10 (PARAMETERS_ERROR_PROB_2_POW_MINUS_165)
    lvl20param: t=5, basebit=3
  Add AHlvl1param and AHlvl2param structs required by cloudkey.

- include/mulfft.hpp: fix NTT dispatch for AHlvl1param when lvl1param
  uses T=uint64_t (tfhe-rs.hpp case). AHlvl1param shares the same ring
  as lvl1param (nbit=9, n=512) so it must use the lvl1 NTT tables, not
  the lvl2 tables (n=1024).

- test/pbs_tfhers.cpp: new benchmark — 1000 HomNAND gates using
  lvl01param/lvl10param with USE_TFHE_RS parameters; outputs ms/gate
  and verifies correctness.

- bench-tfhers/: standalone Rust crate that benchmarks tfhe-rs boolean
  NAND gate with DEFAULT_PARAMETERS using the same parameter set.
  Expects ../tfhe-rs/tfhe as a path dependency.

- .github/workflows/compare-tfhers.yml: CI workflow on Ubuntu 24.04
  that builds both sides and runs the comparison.

- compare-tfhers.def: Apptainer definition (Ubuntu 24.04) for local
  reproducible benchmarking; copies TFHEpp source via %files, clones
  tfhe-rs in %post, builds both binaries, runs both in %runscript.

- README.md: add "Comparison with tfhe-rs" section with parameter
  table, results (TFHEpp 6.66 ms vs tfhe-rs 5.997 ms per NAND gate),
  CPU info (AMD Ryzen 9 9950X3D), and reproduce instructions.

Co-Authored-By: Claude Sonnet 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/.github/workflows/compare-tfhers.yml b/.github/workflows/compare-tfhers.yml
@@ -0,0 +1,82 @@
+name: Compare with tfhe-rs
+
+# Runs on every push and can also be triggered manually.
+on:
+  push:
+  workflow_dispatch:
+
+jobs:
+  compare-pbs:
+    name: PBS benchmark (TFHEpp vs tfhe-rs) on Ubuntu 24.04
+    runs-on: ubuntu-latest
+    container:
+      image: ubuntu:24.04
+
+    steps:
+      # ── System dependencies ───────────────────────────────────────────────
+      - name: Install system dependencies
+        run: |
+          apt-get update
+          DEBIAN_FRONTEND=noninteractive apt-get install -y \
+            build-essential g++ libomp-dev cmake ninja-build git \
+            curl wget ca-certificates
+
+      # ── Rust toolchain (rustup) ───────────────────────────────────────────
+      - name: Install Rust via rustup
+        run: |
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
+            | sh -s -- -y --default-toolchain stable --no-modify-path
+          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
+
+      # ── Checkout TFHEpp ───────────────────────────────────────────────────
+      - name: Checkout TFHEpp
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      # ── Clone tfhe-rs alongside TFHEpp ───────────────────────────────────
+      # Layout expected by bench-tfhers/Cargo.toml:
+      #   $GITHUB_WORKSPACE/            ← TFHEpp root
+      #   $GITHUB_WORKSPACE/tfhe-rs/    ← tfhe-rs clone
+      - name: Clone tfhe-rs
+        run: |
+          git clone --depth 1 https://github.com/zama-ai/tfhe-rs.git tfhe-rs
+
+      # ── Build TFHEpp pbs_tfhers benchmark ────────────────────────────────
+      - name: Build TFHEpp (USE_TFHE_RS, Release)
+        run: |
+          cmake . -B build -G Ninja \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DUSE_TFHE_RS=ON \
+            -DENABLE_TEST=ON
+          cmake --build build --target pbs_tfhers
+
+      # ── Build tfhe-rs Rust benchmark ──────────────────────────────────────
+      - name: Install pinned Rust toolchain (from tfhe-rs/rust-toolchain.toml)
+        working-directory: bench-tfhers
+        run: rustup show  # triggers toolchain download from rust-toolchain.toml
+
+      - name: Build tfhe-rs benchmark (Release)
+        working-directory: bench-tfhers
+        run: cargo build --release
+
+      # ── Show machine info ─────────────────────────────────────────────────
+      - name: Machine info
+        run: |
+          echo "=== CPU info ==="
+          lscpu | grep -E "Model name|CPU\(s\)|Thread|MHz" || true
+          echo "=== Memory ==="
+          free -h || true
+
+      # ── Run benchmarks and compare ────────────────────────────────────────
+      - name: Run TFHEpp pbs_tfhers
+        run: |
+          echo "=== TFHEpp NAND gate (USE_TFHE_RS parameters) ==="
+          echo "Parameters: n=805, k=3, N=512, pbs_level=2, pbs_base_log=10"
+          build/test/pbs_tfhers
+
+      - name: Run tfhe-rs benchmark
+        run: |
+          echo "=== tfhe-rs NAND gate (DEFAULT_PARAMETERS) ==="
+          echo "Parameters: n=805, k=3, N=512, pbs_level=2, pbs_base_log=10"
+          bench-tfhers/target/release/pbs-tfhers-bench
diff --git a/README.md b/README.md
@@ -128,6 +128,56 @@ make
 ./test/test-bootstrapping-fft-spqlios-fma 
 ```
 
+# Comparison with tfhe-rs
+
+TFHEpp can be benchmarked directly against [tfhe-rs](https://github.com/zama-ai/tfhe-rs) using
+identical parameters (`DEFAULT_PARAMETERS`, 132-bit security, boolean API).
+
+## Parameter set
+
+Both sides use exactly the same parameters:
+
+| Parameter | Value | Description |
+|:---:|:---:|:---|
+| `n` | 805 | LWE dimension |
+| `k` | 3 | GLWE dimension |
+| `N` | 512 | Polynomial size |
+| `pbs_level` | 2 | PBS decomposition levels |
+| `pbs_base_log` | 10 | PBS decomposition log-base |
+| `ks_level` | 5 | Key-switch decomposition levels |
+| `ks_base_log` | 3 | Key-switch decomposition log-base |
+
+On TFHEpp's side, enable these with `-DUSE_TFHE_RS=ON`.
+The operation benchmarked is one boolean NAND gate (linear combination + PBS + key switch).
+
+## Results
+
+Measured with `apptainer run compare-tfhers.sif` (Ubuntu 24.04, single-threaded).
+
+**CPU**: AMD Ryzen 9 9950X3D 16-Core Processor (max 5752 MHz)
+
+| Library | Time per NAND gate |
+|:---:|:---:|
+| **TFHEpp** (C++, SPQLIOS-AVX512, `-O3`) | **6.66 ms** |
+| **tfhe-rs** (Rust, `DEFAULT_PARAMETERS`) | **5.997 ms** |
+
+## Reproducing locally (Apptainer)
+
+Requires Apptainer and internet access to clone tfhe-rs and pull the Ubuntu 24.04 image.
+
+```bash
+git clone --recurse-submodules https://github.com/virtualsecureplatform/TFHEpp
+cd TFHEpp
+apptainer build compare-tfhers.sif compare-tfhers.def
+apptainer run compare-tfhers.sif
+```
+
+## CI
+
+The comparison runs automatically on every push via
+[`.github/workflows/compare-tfhers.yml`](.github/workflows/compare-tfhers.yml)
+using an Ubuntu 24.04 container.
+
 # Theory
 
 Here is the slides (in japanese).
diff --git a/bench-tfhers/Cargo.toml b/bench-tfhers/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "pbs-tfhers-bench"
+version = "0.1.0"
+edition = "2021"
+# Minimum Rust version required by tfhe-rs
+rust-version = "1.82"
+
+# tfhe-rs is expected at ../tfhe-rs relative to the TFHEpp repository root.
+# The CI workflow and Apptainer definition both set up this layout:
+#
+#   <workspace>/
+#   ├── TFHEpp/              ← this repository
+#   │   ├── bench-tfhers/   ← this crate
+#   │   └── tfhe-rs/        ← tfhe-rs clone  (git clone … TFHEpp/tfhe-rs)
+#
+# To build manually from the TFHEpp root:
+#   git clone --depth 1 https://github.com/zama-ai/tfhe-rs.git tfhe-rs
+#   cargo build --release --manifest-path bench-tfhers/Cargo.toml
+
+[dependencies]
+tfhe = { path = "../tfhe-rs/tfhe", default-features = false, features = ["boolean"] }
diff --git a/bench-tfhers/rust-toolchain.toml b/bench-tfhers/rust-toolchain.toml
@@ -0,0 +1,3 @@
+# Keep in sync with tfhe-rs/rust-toolchain.toml
+[toolchain]
+channel = "1.91.1"
diff --git a/bench-tfhers/src/main.rs b/bench-tfhers/src/main.rs
@@ -0,0 +1,63 @@
+// pbs_tfhers — tfhe-rs boolean NAND gate benchmark for comparison with TFHEpp.
+//
+// Uses tfhe-rs DEFAULT_PARAMETERS which matches the updated TFHEpp tfhe-rs.hpp:
+//   lwe_dimension  : 805   (n)
+//   glwe_dimension : 3     (k)
+//   polynomial_size: 512   (N)
+//   pbs_base_log   : 10    (Bgbit)
+//   pbs_level      : 2     (l)
+//   ks_base_log    : 3     (basebit)
+//   ks_level       : 5     (t)
+//   lwe_std_dev    : 5.86e-6
+//   glwe_std_dev   : 9.32e-10
+//   security       : 132-bit, p-fail = 2^-64.344
+//
+// Outputs one line: "<ms-per-gate>ms"
+// Followed by "Passed" if correctness checks pass.
+//
+// Matching C++ benchmark: test/pbs_tfhers.cpp
+
+use std::time::Instant;
+use tfhe::boolean::prelude::*;
+
+fn main() {
+    const NUM_TESTS: usize = 1000;
+
+    // Key generation uses DEFAULT_PARAMETERS internally.
+    // This is the slow step (bootstrapping key generation); not timed.
+    let (client_key, server_key) = gen_keys();
+
+    // Prepare random inputs
+    let inputs_a: Vec<bool> = (0..NUM_TESTS).map(|i| i % 2 == 0).collect();
+    let inputs_b: Vec<bool> = (0..NUM_TESTS).map(|i| (i / 2) % 2 == 0).collect();
+
+    let ct_a: Vec<Ciphertext> = inputs_a.iter().map(|&b| client_key.encrypt(b)).collect();
+    let ct_b: Vec<Ciphertext> = inputs_b.iter().map(|&b| client_key.encrypt(b)).collect();
+
+    // Warmup: one gate to ensure JIT / cache effects are settled
+    let _ = server_key.nand(&ct_a[0], &ct_b[0]);
+
+    // Timed benchmark
+    let start = Instant::now();
+    let results: Vec<Ciphertext> = ct_a
+        .iter()
+        .zip(ct_b.iter())
+        .map(|(a, b)| server_key.nand(a, b))
+        .collect();
+    let elapsed = start.elapsed();
+
+    let ms_per_gate = elapsed.as_secs_f64() * 1000.0 / NUM_TESTS as f64;
+    println!("{:.3}ms", ms_per_gate);
+
+    // Correctness check
+    for (i, ct_res) in results.iter().enumerate() {
+        let expected = !(inputs_a[i] && inputs_b[i]);
+        let got = client_key.decrypt(ct_res);
+        assert_eq!(
+            got, expected,
+            "NAND({}, {}) = {} but expected {}",
+            inputs_a[i], inputs_b[i], got, expected
+        );
+    }
+    println!("Passed");
+}
diff --git a/compare-tfhers.def b/compare-tfhers.def
@@ -0,0 +1,111 @@
+Bootstrap: docker
+From: ubuntu:24.04
+
+# ============================================================================
+# compare-tfhers.def — Apptainer image for local TFHEpp vs tfhe-rs comparison
+#
+# Build (from the TFHEpp repository root, submodules must be initialised):
+#   git submodule update --init --recursive   # if not done yet
+#   apptainer build compare-tfhers.sif compare-tfhers.def
+#
+# Run the benchmark:
+#   apptainer run compare-tfhers.sif
+#
+# Both sides use identical parameters (tfhe-rs DEFAULT_PARAMETERS, 132-bit):
+#   n=805, k=3, N=512, pbs_level=2, pbs_base_log=10,
+#   ks_level=5, ks_base_log=3
+# ============================================================================
+
+%labels
+    Description TFHEpp vs tfhe-rs NAND-gate PBS comparison on Ubuntu 24.04
+
+%environment
+    export PATH="/root/.cargo/bin:${PATH}"
+    export WORKSPACE="/opt/tfhe-compare"
+
+# Copy the local TFHEpp source tree (including initialised submodules) into
+# the container at build time.  Run `apptainer build` from the TFHEpp root.
+%files
+    CMakeLists.txt         /opt/tfhe-compare/TFHEpp/CMakeLists.txt
+    include                /opt/tfhe-compare/TFHEpp/include
+    src                    /opt/tfhe-compare/TFHEpp/src
+    test                   /opt/tfhe-compare/TFHEpp/test
+    bench-tfhers           /opt/tfhe-compare/TFHEpp/bench-tfhers
+    thirdparties           /opt/tfhe-compare/TFHEpp/thirdparties
+
+%post
+    export DEBIAN_FRONTEND=noninteractive
+    export PATH="/root/.cargo/bin:${PATH}"
+    export WORKSPACE="/opt/tfhe-compare"
+
+    # ── System packages ──────────────────────────────────────────────────────
+    apt-get update
+    apt-get upgrade -y
+    apt-get install -y \
+        build-essential g++ libomp-dev cmake ninja-build \
+        git curl wget ca-certificates
+
+    # ── Rust toolchain (stable + let tfhe-rs pin its own version) ────────────
+    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
+        | sh -s -- -y --default-toolchain stable --no-modify-path
+
+    # ── Clone tfhe-rs alongside TFHEpp ───────────────────────────────────────
+    # bench-tfhers/Cargo.toml expects: ../tfhe-rs/tfhe (relative to bench-tfhers/)
+    cd "${WORKSPACE}/TFHEpp"
+    git clone --depth 1 https://github.com/zama-ai/tfhe-rs.git tfhe-rs
+
+    # ── Build TFHEpp pbs_tfhers benchmark ────────────────────────────────────
+    cmake . -B build -G Ninja \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DUSE_TFHE_RS=ON \
+        -DENABLE_TEST=ON
+    cmake --build build --target pbs_tfhers
+
+    # ── Build tfhe-rs Rust benchmark ─────────────────────────────────────────
+    cd bench-tfhers
+    # Download the Rust toolchain pinned in rust-toolchain.toml
+    rustup show
+    cargo build --release
+    cd ..
+
+    # Remove large intermediate artefacts to keep image size small
+    rm -rf build/_deps build/CMakeFiles
+
+%runscript
+    export PATH="/root/.cargo/bin:${PATH}"
+    TFHEPP_ROOT="/opt/tfhe-compare/TFHEpp"
+
+    echo "============================================================"
+    echo "  TFHEpp vs tfhe-rs — NAND gate bootstrap comparison"
+    echo "  Parameter set: tfhe-rs DEFAULT_PARAMETERS (132-bit security)"
+    echo "    n=805  k=3  N=512  pbs_level=2  pbs_base_log=10"
+    echo "    ks_level=5  ks_base_log=3"
+    echo "============================================================"
+    echo ""
+
+    echo "--- Machine info ---"
+    lscpu 2>/dev/null | grep -E "Model name|CPU\(s\)|Thread|MHz" || true
+    free -h 2>/dev/null || true
+    echo ""
+
+    echo "--- TFHEpp (C++, USE_TFHE_RS) ---"
+    "${TFHEPP_ROOT}/build/test/pbs_tfhers"
+    echo ""
+
+    echo "--- tfhe-rs (Rust, DEFAULT_PARAMETERS) ---"
+    "${TFHEPP_ROOT}/bench-tfhers/target/release/pbs-tfhers-bench"
+    echo ""
+    echo "Done."
+
+%help
+    Runs a NAND gate bootstrapping benchmark comparing TFHEpp and tfhe-rs
+    using identical parameters (tfhe-rs DEFAULT_PARAMETERS, 132-bit security).
+
+    Prerequisites (on the build host):
+        git submodule update --init --recursive
+
+    Build the image (requires internet access, run from TFHEpp root):
+        apptainer build compare-tfhers.sif compare-tfhers.def
+
+    Run:
+        apptainer run compare-tfhers.sif
diff --git a/include/mulfft.hpp b/include/mulfft.hpp
@@ -60,7 +60,10 @@ constexpr uint64_t lvl1P = 1073707009;
 template <class P>
 inline void TwistNTT(Polynomial<P> &res, PolynomialNTT<P> &a)
 {
-    if constexpr (std::is_same_v<P, lvl1param>)
+    // AHlvl1param shares the same polynomial ring as lvl1param (same nbit/n),
+    // so it uses the lvl1 NTT tables regardless of its Torus type.
+    if constexpr (std::is_same_v<P, lvl1param> ||
+                  std::is_same_v<P, AHlvl1param>)
 #ifdef USE_HEXL
     {
         std::array<uint64_t, lvl1param::n> temp;
@@ -69,7 +72,7 @@ inline void TwistNTT(Polynomial<P> &res, PolynomialNTT<P> &a)
         for (int i = 0; i < lvl1param::n; i++) res[i] = (temp[i] << 32) / lvl1P;
     }
 #else
-        cuHEpp::TwistNTT<typename lvl1param::T, lvl1param::nbit>(
+        cuHEpp::TwistNTT<typename P::T, P::nbit>(
             res, a, (*ntttablelvl1)[0], (*ntttwistlvl1)[0]);
 #endif
     else if constexpr (std::is_same_v<typename P::T, uint64_t>)
@@ -125,7 +128,10 @@ inline void TwistFFTrescale(Polynomial<P> &res, const PolynomialInFD<P> &a)
 template <class P>
 inline void TwistINTT(PolynomialNTT<P> &res, const Polynomial<P> &a)
 {
-    if constexpr (std::is_same_v<P, lvl1param>)
+    // AHlvl1param shares the same polynomial ring as lvl1param (same nbit/n),
+    // so it uses the lvl1 NTT tables regardless of its Torus type.
+    if constexpr (std::is_same_v<P, lvl1param> ||
+                  std::is_same_v<P, AHlvl1param>)
 #ifdef USE_HEXL
     {
         std::array<uint64_t, lvl1param::n> temp;
diff --git a/include/params/tfhe-rs.hpp b/include/params/tfhe-rs.hpp
diff --git a/test/pbs_tfhers.cpp b/test/pbs_tfhers.cpp

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+# Keep in sync with tfhe-rs/rust-toolchain.toml`
	`2`	`+[toolchain]`
	`3`	`+channel = "1.91.1"`