DevOTechS: Huge Integer Math and Encryption Library (HIME)
- A dll for implementing public and secret key encryption using RSA, AES, SHA-256. Also contains functions for prime number generation, random number generation and huge integer operations.
- http://www.devotechs.com/

Entrust Dev-Net
- A variety of tools to add PKI functionality to your application.
- http://www.entrust.com/pki/toolkits.htm

Crypto++
- Free library of cryptographic schemes: includes ciphers, message authentication codes, one-way hash functions, public-key cryptosystems, and key agreement schemes.
- http://www.cryptopp.com/

JavaScript Encryption Program
- Open source JavaScript implementation of the MD5 hash and RC4, AES, CSR and RSA ciphers.
- http://home.versatel.nl/MAvanEverdingen/Code/

SoftaCrypt
- Java based implementation libaries for encryption and hash algorithms.
- http://www.softabar.com/software/softacrypt/

Python Cryptography Toolkit
- A collection of cryptographic algorithms and protocols, implemented for use from Python.
- http://www.amk.ca/python/code/crypto

FastCRC Library
- Optimized implementation of CRC32, CRC16 and CRC16C (CRC-CCITT) checksum algorithms. With examples in C/C++ and Visual Basic.
- http://www.slavasoft.com/fastcrc

Botan
- An open-source C++ crypto library that includes block and stream ciphers, hash functions, MACs, and public key algorithms, along with an easy to use filter-based interface.
- http://botan.randombit.net/

SlavaSoft QuickHash Library
- Add hash (MD2, MD5, SHA-1, SHA-2, RIPEMD-160, PANAMA, TIGER), checksum (CRC32, ADLER32) and HMAC (HMAC-MD5, HMAC-SHA1, HMAC-SHA256, HMAC-SHA384, HMAC-SHA512, HMAC-RIPEMD160, HMAC-PANAMA, HMAC-TIGER) calculations to your Windows apps quickly and easily. C+
- http://www.slavasoft.com/quickhash

Punkroy and the Cypher Project
- Collection of programming examples on encryption including: file encryption, steganography in images and sound, data base record encryption, and password verification. All written in Pascal, all source code available.
- http://drque.net/Punkroy/Programs.html

QuartzLight in Java
- Implements the public key signature system QuartzLight in Java where QuartzLight refers to a research version of the Quartz standard.
- http://www.christopher-wolf.de/ql/

SSL++ -- C++ Wrapper arround OpenSSL library
- SSL++ is simple C++ library encapsulating OpenSSL functionality to make it simple and easily accessible to C++ programmers.
- http://www.total-knowledge.com/progs/sslpp

PrimeInk
- Tools to work with X.509 certificates and revocation lists, various security syntax and messaging formats, a time stamping API, public key encryption algorithms, key exchange protocols, and a range of secure hash functions. Lists types of uses and compat
- http://www.cryptomathic.com/products/primeink_index.html

Hidden Field Equations (HFE) in Java
- A free implementation of the public key cryptography system with source code and documentation.
- http://www.christopher-wolf.de/hfe/

Snapcrypt - Cryptography Algorithms
- A library for the TMS320C54x DSP, contains algorithms for symmetric block ciphers, one-way hash functions, public key encryption and digital signature.
- http://www.snapshield.com/Products_licensing_fs.html

Dragonate Technologies Ltd.
- Offers Elliptic Curve software. including ECDSACom, an ActiveX control, and borZoi, an open source library. Includes product descriptions and contact information.
- http://www.dragongate-technologies.com/products.html

TPCrypt by Technology Pathways LLC
- Cryptographic classes for Microsoft .NET. Includes DES, TripleDES, RC2, and Rijndael (AES) implementations.
- http://www.TechPathways.com/DesktopDefault.aspx?tabindex=3&tabid=3

RSA MD5 Visual C++
- An implementation of the message digest algorithm. Includes a performance measurement facility.
- http://www.langfine.com/rsa_md5.htm

MD5 Homepage (unofficial)
- Information and implementation in various languages.
- http://userpages.umbc.edu/~mabzug1/cs/md5/md5.html

RC-Crypt
- Implementation of RC5 (128) in C.
- http://www.ricksoft.co.uk/downloads/rccrypt/rccrypt.htm

Applied Cryptography Code
- The code from the Applied Cryptography disk, available outside the US.
- ftp://ftp.zedz.net/pub/crypto/applied-crypto/

CypherMath - Cryptographic Math Package
- Gives your applications access to multi-precision integer math routines with just a function call. Full source code available. For VB, C++, or embedded systems.
- http://www.cyphercalc.com/math

Network Security Services
- Mozilla's NSS, is a set of libraries designed to support cross-platform development of security-enabled server applications.
- http://mozilla.org/projects/security/pki/nss/

libmcrypt
- Supports the following algorithms; BLOWFISH, TWOFISH, DES, TripleDES, 3-WAY, SAFER-sk64, SAFER-sk128, SAFER+, LOKI97, GOST, RC2, RC6, MARS, IDEA, RIJNDAEL-128 (AES), RIJNDAEL-192, RIJNDAEL-256, SERPENT, CAST-128, CAST-256, ARCFOUR and WAKE. ANSI C.
- http://mcrypt.hellug.gr/#_libmcrypt

CTC
- CTClib (PGP-interoperable ANSI C encryption software library) and CTCjava (Java crypto components and application).
- http://www.bifroest.demon.co.uk/ctc/

BSAFEeay
- A free, public domain implementation of RSA Data Security's BSAFE API, using the SSLeay crypto library.
- https://www.cypherpunks.to/bsafeeay/

Emacs Cryptographic Library and Tools
- Includes code for IDEA, Blowfish, SHA-1, MD5, RC16 (RC4 extension), an initial implementation of DES and a few related toys.
- http://web.mit.edu/thouis/www/ecrypto.html

OpenSSL
- A collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography
- http://www.openssl.org/