# libsodium [NaCl](http://nacl.cr.yp.to/) (pronounced "salt") is a new easy-to-use high-speed software library for network communication, encryption, decryption, signatures, etc. NaCl's goal is to provide all of the core operations needed to build higher-level cryptographic tools. Sodium is a portable, cross-compilable, installable, packageable version of NaCl, binary-compatible with NaCl. ## Portable In order to pick the fastest working implementation of each primitive, NaCl performs tests and benchmarks at compile-time. Unfortunately, the resulting library is not garanteed to work on different hardware. Sodium currently only ships portable reference implementations. Optimized implementations (including NEON optimizations) will eventually be supported, but tests and benchmarks will be performed at run-time, so that the same binary package can still run everywhere. Sodium is tested on a variety of compilers and operating systems, including Windows, iOS and Android. ## Installable Sodium is a shared library with a machine-independant set of headers, so that it can easily be used by 3rd party projects. The library is built using autotools, making it easy to package. Installation is trivial, and both compilation and testing can take advantage of multiple CPU cores: ./configure make make check make install ## Comparison with vanilla NaCl The default public-key signature system in NaCl was a prototype that shouldn't be used any more. Sodium ships with the SUPERCOP reference implementation of [Ed25519](http://ed25519.cr.yp.to/), and uses this system by default for `crypto_sign*` operations. For backward compatibility, the previous system is still compiled in, as `crypto_sign_edwards25519sha512batch*`. ## Additional features The Sodium library provides some convenience functions in order to retrieve the current version of the library: const char *sodium_version_string(void); const int sodium_version_major(void); const int sodium_version_minor(void); Headers are installed in `${prefix}/include/sodium`. A convenience header includes everything you need to use the library: #include <sodium.h>