This is a C-language software library that provides optimized implementations of the Diffie-Hellman functions known as X25519 and X448 (RFC-7748) for 64-bit architectures.
This source code is part of the research work titled: "How to (pre-)compute a ladder" by the authors:
- Thomaz Oliveira, Computer Science Department, Cinvestav-IPN, Mexico.
- Julio López, University of Campinas, Brazil.
- Hüseyin Hisil, Yasar University, Turkey.
- Armando Faz-Hernández, University of Campinas, Brazil.
- Francisco Rodríguez-Henríquez, Computer Science Department, Cinvestav-IPN, Mexico.
A peer-reviewed paper was presented in the 24th Annual Conference on Selected Areas in Cryptography (SAC2017).
- Paper [DOI]
- Slides [PDF].
- Pre-print (IACR ePrint Archive) http://iacr.eprint.org/2017/264 [PDF]
To cite this work use:
@inproceedings{oliveira_sac2017,
author = {Thomaz Oliveira and Julio L\'opez and
H\"useyin H{\i}\c{s}{\i}l and Armando Faz-Hern\'andez and
Francisco Rodr\'iguez-Henr\'iquez},
editor = {Adams, Carlisle and Camenisch, Jan},
title = {How to (pre-)compute a ladder},
booktitle = {Selected Areas in Cryptography – SAC 2017:
24th International Conference, Ottawa, Ontario,
Canada, August 16 - 18, 2017, Revised Selected Papers},
year = {2018},
publisher = {Springer International Publishing},
pages = {172-191},
doi = {10.1007/978-3-319-72565-9_9},
}
- Prime field arithmetic is optimized for the 4th and 6th generation of Intel Core processors (Haswell and Skylake micro-architectures).
- Efficient integer multiplication using MULX instruction.
- Integer additions accelerated with ADCX/ADOX instructions.
- Key generation uses a read-only table of 8 KB (25 KB) for X25519 (X448).
- It follows secure coding countermeasures.
This library is a standalone C-language code. However, for tests we use C++ code.
- C and C++ compilers.
- git
- cmake
First, clone the repository and configure project using the CMake tool:
$ git clone https://github.com/armfazh/rfc7748_precomputed
$ cd rfc7748_precomputed
$ mkdir build
$ cd build
To specify an alternative C/C++ compiler set the following variables:
$ CC=gcc CXX=g++ cmake ..
Also, to specify a custom install directory (install_dir
) use:
$ cmake -DCMAKE_INSTALL_PREFIX=install_dir ..
Finally, compile and install:
$ make
$ make install (optional)
Once compilation was done, you can run some companion programs.
For running a sample program use:
$ bin/sample_x25519
$ bin/sample_x448
For running a performance benchmark (in clock cycles) use:
$ make bench
$ bin/bench
For running the Google benchmark tool use:
$ make gbench
$ bin/gbench --benchmark_repetitions=10 --benchmark_display_aggregates_only=true
For running the Google Test tool use:
$ make tests
$ bin/tests
In the fuzz folder, there are several tests against gmp
library and the HACL
project. Read the compilation instructions at fuzz/README.md for more information.
Benchmark performance on 64-bit Intel architectures (table entries are clock cycles).
X25519 | Haswell | Skylake |
---|---|---|
Key Generation | 92,400 | 69,500 |
Shared Secret | 145,800 | 108,700 |
X448 | Haswell | Skylake |
---|---|---|
Key Generation | 401,902 | 322,040 |
Shared Secret | 670,747 | 528,470 |
Haswell is a Core i7-4770 processor.
Skylake is a Core i7-6700K processor.
BSD-3 Clause License (LICENSE)
To report some issues or comments of this project, please use the issues webpage [here].