Files
zeekay b832ba2c39 Initial Torus commit
Forked from upstream concrete (BSD-3-Clause-Clear, © 2024 ZAMA) at HEAD
ecb729bb. Modifications copyright © 2026 Lux Industries Inc.

Rebranding scope:
  - Python module concrete → torus (across frontends/torus-python)
  - Rust module concrete-* → torus-* (across frontends/torus-rust)
  - MLIR dialect concretelang → toruslang (across compilers/torus-compiler)
  - Compiler optimizer concrete-optimizer → torus-optimizer
  - Backend concrete-cpu / concrete-cuda → torus-cpu / torus-cuda
  - Wire protocol concrete-protocol → torus-protocol
  - Parameter-curves concrete-security-curves-* → torus-security-curves-*
  - Public symbols concretelib → toruslib, ConcreteLang → TorusLang
  - URLs github.com/zama-ai/concrete → github.com/luxfhe/torus
  - URLs docs.zama.ai/concrete → docs.luxfhe.com/torus

Legal compliance:
  - LICENSE.txt retains original Copyright © 2024 ZAMA verbatim (§1-§2)
  - LICENSE.txt adds modifications copyright © 2026 Lux Industries Inc.
  - §3 endorsement clause: Torus is marketed exclusively as a Lux product;
    no Zama name used in README, docs, or marketing
  - NOTICE file provides factual attribution per legal best practice
    (not endorsement; required by upstream BSD-3-Clause-Clear)

README + NOTICE rewritten from scratch with Lux brand:
  - Quick-start in Python (torus.fhe)
  - Architecture diagram showing the gen-1 vtbl integration path
    (luxcpp/gpu → lux-private/gpu-kernels for CUDA/Metal/WebGPU)
  - Scheme coverage table: TFHE (luxfi/fhe), CKKS/BGV/BFV (luxfi/lattice)
  - Lux FHE family table: Torus / TorusVM / TorusEVM / TorusML / TorusNet

Known limitations (phase-2A scope):
  - PyPI package torus-fhe not yet published; the torus Python module
    is renamed structurally but pip-installable distribution is a
    follow-up (Phase 2A.1)
  - MLIR dialect rename is text-level; the compiler-internal LLVM
    rebuild (concrete-compiler-internal-llvm-project submodule) is
    structural and works; tablegen files renamed concrete→torus but the
    generated .inc files in the source tree will regenerate at build
    time
  - backends/torus-cuda/implementation/ is an upstream submodule
    pointer to the tfhe-rs source (not fetched in the staging clone);
    the CUDA backend body is delivered out-of-tree
  - ~100 test-fixture variable names like concrete_encoded_sample
    retain "concrete" as a math term (vs symbolic); these are inside
    tests/, not the public API; cleanup is a follow-up commit
  - 295 Python `from concrete import ...` residuals in luxfhe/ml-sdk
    consumer remain; that repo's import update is Phase 2B

This commit is the seed for the luxfhe/torus repo. Push as the first
commit to a fresh GitHub repo; do not re-import upstream Zama git
history.
2026-05-29 14:16:47 -07:00

2.7 KiB

Adding a new backend to the compiler

Context

The Torus backends are implementations of the cryptographic primitives of the Lux Industries variant of TFHE.

There are client features (private and public key generation, encryption and decryption) and server features (homomorphic operations on ciphertexts using public keys).

Considering that

  • performance improvements are mostly beneficial for the server operations
  • the client needs to be portable for the variety of clients that may exist, we expect mostly server backend to be added to the compiler to improve performance (e.g. by using specialized hardware)

What is needed in the server backend

The server backend should expose C or C++ functions to do TFHE operations using the current ciphertext and key memory representation (or functions to change representation). A backend can support only a subset of the current TFHE operations.

The most common operations one would be expected to add are WP-PBS (standard TFHE programmable bootstrap), keyswitch and WoP (without padding bootsrap).

Linear operations may also be supported but may need more work since their introduction may interfere with other compilation passes. The following example does not include this.

Torus-cuda example

We will detail how torus-cuda is integrated in the compiler. Adding a new server feature backend (for non linear operations) should be quite similar. However, if you want to integrate a backend but it does not fit with this description, please open an issue or contact us to discuss the integration.

In compilers/torus-compiler/Makefile

  • the variable CUDA_SUPPORT has been added and set to OFF (CUDA_SUPPORT?=OFF) by default
  • the variables CUDA_SUPPORT and CUDA_PATH are passed to CMake
-DTORUSLANG_CUDA_SUPPORT=${CUDA_SUPPORT}
-DCUDAToolkit_ROOT=$(CUDA_PATH)

In compilers/torus-compiler/compiler/include/toruslang/Runtime/context.h, the RuntimeContext struct is enriched with state to manage the backend ressources (behind a #ifdef TORUSLANG_CUDA_SUPPORT).

In compilers/torus-compiler/compiler/lib/Runtime/wrappers.cpp, the cuda backend server functions are added (behind a #ifdef TORUSLANG_CUDA_SUPPORT)

The pass TorusToCAPI is modified to have a flag to insert calls to these new wrappers instead of the cpu ones (the code calling this pass is modified accordingly).

It may be possible to replace the cpu wrappers (with a compilation flag) instead of adding new ones to avoid having to change the pass.

In compilers/torus-compiler/CMakeLists.txt a Section #Torus Cuda Configuration has been added Other CMakeLists.txt have also been modified (or added) with if(TORUSLANG_CUDA_SUPPORT) guard to handle header includes, linking...