Libchop is a set of utilities and library for data backup and distributed storage. Its main application is chop-backup, an encrypted backup program that supports data integrity checks, versioning at little cost, distribution among several sites, selective sharing of stored data, adaptive compression, and more. The library itself, which chop-backup builds upon, implements storage techniques such as content-based addressing, content hash keys, Merkle trees, similarity detection, and lossless compression. It makes it easy to combine them in different ways. The ‘chop-archiver’ and ‘chop-block-server’ tools, illustrated in the manual, provide direct access to these facilities from the command line. It is written in C and has Guile (Scheme) bindings.
jQuery.pidCrypt uses HTML5 localStorage or sessionStorage for implementing an RSA public keyring within the browser, allowing transparent asymmetric encryption of form submissions while protecting the keys with AES symmetric encryption. It is easy to implement and has numerous configurable options for pre, post, and error-handling callbacks.
gpgpwd is a terminal-based password manager. It stores a list of passwords in a GnuPG-encrypted file, and allows you to easily retrieve, change, and add to that file as needed. It also generates random passwords which you can use, easily allowing you to have one "master password" (for your gpg key), with one unique and random password for each website or service you use, ensuring that your other accounts stay safe even if one password gets leaked. gpgpwd can also utilize git to allow you to easily synchronize your passwords between different machines.
LibRCrypt is an Objective C library for complex data encryption based on Rubik's Cubes. The idea's pretty simple: If you represent data as the squares on a Rubik's Cube, you can apply transformations to the data and get back encrypted data, all of which is commutatitive. Just as a Rubik's Cube can be solved if you know all of the moves, this data can be "unwound", so to speak, if you know all of the transforms applied, but the encryption is even deeper than that. A cube can only cover (9 squares per face x 6 faces) 54 significant bits of data. Therefore, compressed data must be composed of multiple (even thousands) of Rubik's Cubes.