FourQ_32bit

FourQlib v3.0 (C Edition): portable 32-bit implementation

Contents

The FourQ_32bit folder contains:

• FourQ_32bit/Visual Studio/: folder with Visual Studio 2015 solution and project files for compilation and testing in Windows.
• FourQ_32bit/makefile: Makefile for compilation using GNU GCC or clang compilers on Linux.
• Main .c and .h files: library and header files. Public API for ECC scalar multiplication, key exchange and signatures is in FourQ_32bit/FourQ_api.h.
• FourQ_32bit/generic/: folder with library files for 32-bit implementation.
• FourQ_32bit/tests/: test files.
• FourQ_32bit/README.md: this readme file.

Supported platforms

This implementation is supported on 32-bit platforms such as x86 and ARM-based processors running Windows or Linux. We have tested the library with Microsoft Visual Studio 2015, GNU GCC v4.9 and clang v3.8.

See instructions below to choose an implementation option and compile on one of the supported platforms.

Complementary crypto functions

Random values are generated with /dev/urandom in the case of Linux, and with the function BCryptGenRandom() in the case of Windows.

The library includes an implementation of SHA-512 which is used by default by SchnorrQ signatures.

Users can experiment with different options by replacing functions in the random and sha512 folders and applying the corresponding changes to the settings in FourQ.h.

Instructions for Windows

Building the library with Visual Studio

Open the solution file (FourQ.sln) in Visual Studio 2015, select the "Generic" configurations from the Solution Configurations menu (Win32 should appear as Solution Platform).

By default, USE_ENDO=true is defined. To modify this configuration, go to the property window of the FourQ project, go to Configuration Properties > C/C++ > Preprocessor. Make any suitable changes, e.g., USE_ENDO=true or false. Repeat these steps for the fp_tests, ecc_tests and crypto_tests projects.

Finally, select "Build Solution" from the "Build" menu.

Running the tests

After building the solution, run fp_tests.exe, ecc_tests.exe and crypto_tests.exe.

Using the library

After building the solution, add the FourQ.lib file to the set of References for a project, and add FourQ.h and FourQ_api.h to the list of header files of a project.

Instructions for Linux

Building the library and executing the tests with GNU GCC or clang

To compile on Linux using the GNU GCC compiler or the clang compiler, execute the following command from the command prompt:

$ make ARCH=[x86/ARM] CC=[gcc/clang] USE_ENDO=[TRUE/FALSE] EXTENDED_SET=[TRUE/FALSE] CACHE_MEM=[TRUE/FALSE]

After compilation, run fp_tests, ecc_tests or crypto_tests.

By default GNU GCC is used, as well as endomorphisms and extended settings. Similarly, CACHE_MEM=TRUE is set by default indicating that the targeted platform contains a cache memory.

For example, to compile using clang with the efficient endomorphisms on an x86 machine, execute:

$ make ARCH=x86 CC=clang

As another example, to compile using GNU GCC with the efficient endomorphisms on an ARM machine, execute:

$ make ARCH=ARM

By default EXTENDED_SET is enabled, which sets the following compilation flags: -fwrapv -fomit-frame-pointer -march=native. To disable this, use EXTENDED_SET=FALSE. Users are encouraged to experiment with the different flag options.