Free encryption and decryption software for linux

Gaim-Encryption uses NSS to provide transparent RSA encryption as a Gaim plugin.
Main features:
- Automatically creates a public/private key pair for you upon loading the plugin
- Automatically transmits your public key to other users.
- Supports 512 - 4096 bit keys.
- Saves keys of known users, and warns you if their public key has changed.
- Embeds all encryption and keys inside HTML, so if the other user doesnt have the plugin, they will get a little message telling them about the plugin, and wont get a screen full of garbage.
- Stores keys in human readable files in your .gaim directory, in case you ever need to copy/edit them by hand. Which you really shouldnt have to do.
- Automatically recognizes if you are chatting with someone who has the plugin- see the Preferences dialog.
- Available for the Windows version of Gaim.
- Modular and extensible. If you want to define a different type of encryption, you can use this plugin as a wrapper to take care of transporting the encrypted binary over the IM pipe.

CryptoBox project wants to bring data encryption to the masses. CryptoBox project provides two packages: CryptoBox-Server and CryptoBox-CD.
The CryptoBox-Server package adds hard disk encryption to a file server (running Samba, NFS, DAV, etc.) without annoying its users.
The CryptoBox-CD is targeted at users who want to set up an encrypting file server without bothering about complicated administration issues.
Enhancements:
- A Spanish translation was added.
- A Debian package is now also available for the ARM architecture.

Eureka Messenger 4 software delivers secure and private messaging and unlimited file transfers over the internet.

This application no longer requires the VB Runtimes, but this new version 4 is not compatible with the previous windows version.

Installation:

Actually there is no install for this application. You can run it right where you unzipped it, or copy the files unzipped wherever you want them.

If there is a firewall on either machine, some configuration may be required in order to make a connection.

The program has a Help file to guide you on how it works, although it is simple enough to run without much assistance.

You probably need to issue a chmod +x messenger before it can run. On some linux systems you may also need to issue a chmod +755 messenger.

Come And Go Encryption provides an encryption program based off one-time pads.
Cum And Go Encryption is a very basic program to encrypt or decrypt a program using a variant of the one-time pad. This allows for almost uncrackable encryption.
Why is it still crackable? The program uses one relatively small key to XOR the contents of another file, encrypting it.
A one-time pad uses a very large key (about the same size as the file/data to encrypt) and is completely random. Still, the encryption is good enough to mask the identity of a program or document, or stop someone from accessing that document or program.
The origins of this program were an effort to stop a specific kind of movie and image from being viewed normally.
Installing is a breeze: simply run the program. Put it anywhere you like, it wont matter as long as you put the full path to the program to encrypt/decrypt.
Run the program to see a basic description of its use.
This program works very well in windows but was designed for use in Linux/UNIX. The stdout option allows for decryption to standard output, allowing one to pipe the programs decrypted data to another program.
This could be used to view an encrypted movie without having to write the whole movie to disk; the only problem with this is that on some Operating Systems pipes are slow and inefficient, especially with a high-bitrate movie. Steps will be taken to speed this up in the future.
Enhancements:
- Fix password use so the password is not shown in "encrypted" files
- Use an actual encryption method, and not a cheesy XOR
- Adapt CAG to use modules such as SHA, Crypt, MD5, and others

cryptmount project is a utility for GNU/Linux operating systems which allows an ordinary user to mount an encrypted filesystem.
cryptmount was written to address differences between the capabilities of the loopback device and the newer, preferred, device-mapper mechanisms of the 2.6 kernel series, which make it more difficult for a non-root user to configure the devices necessary for access to an encrypted filesystem.
After the initial configuration of the encrypted filesystem, an ordinary user can mount and unmount the filesystem on demand, solely by providing the decryption password.
Enhancements:
- A new interactive tool to assist with initial setup of encrypted filesystems, support for reading/writing OpenSSL key files via libgcrypt, facilities for translating between key files stored in different formats, and support for improved dismantling of loopback filesystems during system shutdown.

Cryptonit project is a client side cryptographic tool which allows you to encrypt/decrypt and sign/verify files with PKI (Public Key Infrastructure) certificates.
Main features:
- Encryption/decryption based on highly reliable algorithms
- Signature/verification procedures ensuring tamper-proof documents
- Use of passwords, certificates & smart (chip) cards for file encryption
- Address book for saving and organizing contacts
- Ability to import contacts and their certificates from the corporate directory (LDAP import)
- Multiple user account management
- Interfaces in both English and French
- CRL download
- RSA cryptography (public key cryptography standard)

Relax and Recover (abbreviated rear) is a highly modular disaster recovery framework for GNU/Linux based systems.
The disaster recovery information (and maybe the backups) can be stored via the network, local on hard disks or USB devices, DVD/CD-R, tape, etc. The result is also a bootable image that is capable of booting via PXE, DVD/CD and tape (OBDR).
Main features:
- Focus on Disaster Recovery
- Modular concept
- For Linux and other Unix-like operations systems
- No external dependancies - use only standard software supplied with the distribution
- encryption (optional) - openssl ?
- Linux: kernel > 2.6 supported (no kernel 2.2/2.4 support !)
- User friendly - minimal output, use log file for error messages and details
The aim is to make rear as least demanding as possible, it will require only the applications neccessary to fulfill the job rear is configured for. All other applications will be copied to the rescue system if they are present.
Enhancements:
- Added SELinux suppport for NETFS Did restore tests with NETFS - see video 2006-08-31 GSS
- Added NETFS support BACKUP=NETFS 2006-08-30 GSS
- finally fixed bug in mkrescue-functions.sh about c0d0p 0 (DEVwP=1)
- Added RHEL ES/AS support 2006-07-21 GD
- start the NFS/CIFS tar backup-restore cyclus
- added support for Software RAID