mcrypt is a program for encrypting files or streams. It is intended to be a replacement for the old UNIX crypt. It uses well-known and well-tested algorithms like BLOWFISH, AES, ARCFOUR, CAST-128, and more in several modes of operation. It also has a compatibility mode with the old UNIX crypt program and the des program found in Solaris.
shash is a program which produces message digests for files, and checks whether the digest remains the same (i.e., whether the files changed). Since anyone can generate the message digest, it may not be suitable for some security-related applications. Because of this, shash also supports HMAC (rfc2104), which is a mechanism for message authentication using cryptographic hash functions. shash can use a key with a hash algorithm to produce hashes that can only be verified with the same key. This way, you can securely check whether files in a filesystem were altered.
The RAZip bitstream format was designed to provide a faster random access to compressed data than what is currently possible using the GZIP format. Its major features include fast random access to compressed data, freedom from patents, single-pass coding/decoding using a bounded amount of intermediate storage, the ability to choose from one of many algorithms for compression, encryption, or error correction, and comprehensive support for Unix file metadata, Macintosh file metadata, and arbitrary file metadata.
Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.
TPassguard is designed for working with Unix systems or the Web, where you need to remember a number of passwords. This program manages passwords in an encrypted file, so that you only have to remember one. It uses the PassGuard Framework and can be interfaced with any kind of encryption via a plugin system.
The PassGuard suite is a set of software that manages your passwords encrypted in a file. You just have to remember one, and different encrypted file formats are supported via plugins. The PassGuard gpasman plugin is the plugin that manages gpasman files encrypted with the RC2 algorithm.
GPassguard is a GTK+ frontend to the *PassGuard suite, which manages passwords in an encrypted file so that you only have to remember one. It uses the PassGuard Framework and can be interfaced with any kind of encryption via a plugin system. It allows you to copy passwords to the clipboard.