aqTFHE2

A header-only library of TFHE in C++17.

Features

• Simple. aqTFHE2 is a single header library; it consists of only aqtfhe2.hpp.
• Fast. About 9 ms/gate on Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz.
• Secure. Users don't have to use insecure PRNGs, but can use their favorite CSPRNGs (e.g. std::random_device).

Simple Usage

Write code like this:

#include "aqtfhe2.hpp"

int main()
{
    using P = aqtfhe2::params::CGGI16;
    std::random_device rand;

    auto sk = aqtfhe2::secret_key<P>::make(rand);
    auto ck = aqtfhe2::cloud_key<P>::make(rand, sk);

    auto e0 = sk.encrypt(rand, false), e1 = sk.encrypt(rand, true);

    auto eres = ck.nand(e0, e1);

    assert(sk.decrypt(eres) == true);
}

And compile it:

$ g++ -std=c++17 -march=native -Ofast hoge.cpp
$ ./a.out

Performance

About 9 ms/gate for old parameter [CGGI16], and 15 ms/gate for new parameter [CGGI19]. Both are measured on Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz.

You can verify it by using main.cpp:

$ make     # Compile main.cpp
$ ./main   # Run
Old parameter [CGGI16]:	8972us / gate
New parameter [CGGI19]:	14963us / gate

See TFHE's web site for the details about old and new parameters.

Caveat

Some functions in aqTFHE2 need a random number generator as argument. Use std::random_device there if you don't care about it, because it is supposed to be the only cryptographically secure pseudo-random number generator (CSPRNG) in C++ standard library (See here for the details).

Licenses

This project is licensed under Apache License Version 2.0. See the file LICENSE.

A part of aqtfhe2.hpp is copied and modified from TFHE. See the comments in aqtfhe2.hpp for the details.

References

• TFHE
• TFHEpp
  • aqTFHE2 is strongly inspired by TFHEpp.
• aqTFHE