The Open-Transactions project is a collaborative effort to develop a robust, commercial-grade, fully-featured, free-software toolkit implementing a full-strength financial cryptography library, API, CLI, and prototype server. Open-Transactions democratizes financial and monetary actions. You can use it for issuing currencies/stock, paying dividends, creating asset accounts, sending/receiving digital cash, writing/depositing cheques, cashier's cheques, creating basket currencies, trading on markets, scripting custom agreements, recurring payments, escrow, etc. Strong crypto is used. Balances are unchangeable (even by a malicious server). Receipts are destructible and redundant. The transactions are unforgeable. The cash is untraceable. The cheques are non-repudiable.
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.
sphlib provides optimized implementations in both C and Java of cryptographic hash functions. The C code includes "small footprint" variants optimized for architectures with low L1 cache (e.g. WiFi routers running OpenWRT). The C code comes with a command-line tool that can serve as a drop-in replacement for md5sum, sha1sum, sha256sum, etc. for all implemented hash functions. The Java code is compatible with J2ME. There are implementations of fourteen "second-round" SHA-3 candidates, for all output lengths: BLAKE, Blue Midnight Wish, CubeHash, ECHO, Fugue, Grøstl, Hamsi, JH, Keccak, Luffa, Shabal, SHAvite-3, SIMD, and Skein. Some pre-SHA-3 hash functions (including MD4, MD5, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, RIPEMD-160, and others) are also implemented.
stegfs is a Fuse based file system which provides absolute security. Using encryption to secure files, and the art of steganography to hide them, stegfs aims to ensure that the existence of such files isn't guaranteed. Implemented as a Fuse based file system and using the mhash and mcrypt libraries to provide the cryptographic hash and symmetric block cipher functions, stegfs is at the cutting edge of secure file system technology.
PolarSSL is a light-weight cryptographic and SSL/TLS library written in C. PolarSSL makes it easy for developers to include cryptographic and SSL/TLS capabilities in their (embedded) applications with as little hassle as possible. Loose coupling of the components inside the library means that it is easy to separate the parts that are needed, without needing to include the total library. PolarSSL is written with embedded systems in mind and has been ported on a number of architectures, including ARM, PowerPC, MIPS, and Motorola 68000. The source is written to have very loose coupling, enabling easy integration of parts in other software projects. Very loosely coupled cryptographic algorithms for MD2, MD4, MD5, SHA1, SHA-256, SHA-512, AES, Camellia, DES, Triple DES, ARC3, and RSA are included.
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.
MEO is a powerful data encryption application to encrypt or decrypt files of any type, including Microsoft Word, email, and PDF documents. It can also create self-extracting encrypted files. This is handy for those who like to view their encrypted files without installing any other encryption software. Also, many downloads supply a checksum or hash value for you to verify the integrity of your download. Meo allows you to create and verify MD5 checksums, SHA-1 hashes, and Tiger Tree hashes.
UsbCryptFormat is a graphical user interface (GUI) for the encryption of USB flash drives or external hard drives. It allows the user to reformat a USB flash drive, an SD card, or an external hard drive with an encrypted filesystem very easily and without the danger of destroying data on an internal hard drive because of incautious handling of device names. So it is usable even for a layperson.