Nettle is a cryptographic library that is designed to fit easily in a wide range of toolkits and applications. It began as a collection of low-level crypto functions from lsh in 2001 . Since June 2009, with version 2.0, it is a GNU package .

As of version 2.1, nettle provides the AES cipher (also known as rijndael) (with assembler optimizations for x86 and sparc), the ARCFOUR (also known as RC4) cipher (with x86 and sparc assembler), the ARCTWO (also known as RC2), BLOWFISH, CAMELLIA (with x86 assembler optimizations), CAST128, DES, the MD2, MD4, and MD5 (with x86 assembler) digests, the SERPENT cipher, the SHA1 (with x86 assembler), SHA224, SHA256, SHA384, and SHA512 digests, the TWOFISH cipher, RSA, and DSA. Most algorithms are based on GMP

GNU Multi-Precision Library

The GNU Multiple Precision Arithmetic Library, also known as GMP, is a free library for arbitrary-precision arithmetic, operating on signed integers, rational numbers, and floating point numbers...

.

Nettle can be used by GnuTLS

GnuTLS

GnuTLS , the GNU Transport Layer Security Library, is a free software implementation of the SSL and TLS protocols. Its purpose is to offer an application programming interface for applications to enable secure communication protocols over their network transport layer.-Features:GnuTLS consists of...

 as an alternative to parts of libgcrypt

Libgcrypt

libgcrypt is a cryptographic library developed as a separated module of GnuPG . It can also be used independently of GnuPG, although it requires its error-reporting library....

.