ACL2 is a mathematical logic, programming language, and mechanical theorem prover based on the applicative subset of Common Lisp. It is an "industrial-strength" version of the NQTHM or Boyer/Moore theorem prover, and has been used for the formal verification of commercial microprocessors, the Java Virtual Machine, interesting algorithms, and so forth.
BeeCrypt is an ongoing project to provide strong and fast cryptography in the form of a toolkit usable by commercial and open source projects. Included in the library are entropy sources, random generators, block ciphers, hash functions, message authentication codes, multiprecision integer routines, and public key primitives.
Bitcoin is a peer-to-peer electronic cash system that is completely decentralized, without the need for a central server or trusted parties. Users hold the crypto keys to their own money and transact directly with each other, with the help of a P2P network to check for double-spending.
Botan is a crypto library written in C++. It provides a variety of cryptographic algorithms, including common ones such as AES, MD5, SHA, HMAC, RSA, Diffie-Hellman, DSA, and ECDSA, as well as many others that are more obscure or specialized. It also offers SSL/TLS (client and server), X.509v3 certificates and CRLs, and PKCS #10 certificate requests. A message processing system that uses a filter/pipeline metaphor allows for many common cryptographic tasks to be completed with just a few lines of code. Assembly and SIMD optimizations for common CPUs offers speedups for critical algorithms like AES and SHA-1.
Bugs Dynamic Cryptography is a private key cryptography algorithm. The package includes a C Library and many sample applications, including ones for file encryption, secure chatting, and login applications. The algorithm handles stream and block encryption, unlimited Keylength, and a strong key generator. Documentation and a developer HOWTO are included.
CDSA stands for Common Data Security Architecture. It provides a security framework that includes cryptographically signed modules to present an abstracted unified API to the application developer to perform cryptographic and security related operations. It also includes hardware support for cryptographic tokens and biometric devices, such as thumbprint scanners. Intel has implemented the CDSA 2 specification and released it as open source.
CryptoTE is a text editor with integrated strong cryptography. It is based on the popular Scintilla widget and automatically stores text data in secure encrypted container files. Compared to other "password keeper" programs, CryptoTE does not force any structure upon your data: it works with plain ASCII text and does not require you to fill in grids, key-value attributes, or descriptions. Encryption is transparently performed using the highly-secure Serpent cipher. The editing interface is thoroughly optimized for speed and ease of use. Multiple subfiles, Quick-Find, and a two-click random password generator make daily use very convenient.