Free encryption programs 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.

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

Eureka Encryption SDK Shared Library allows you to use Eureka Encryption in your own applications. Encrypt or decrypt strings or files.

Eureka Encryption shared Library installation instructions:

Start a terminal session and navigate to the folder where the files are located and enter the following commands:

chmod +x eursdk.so (this may be optional)

cp eursdk.so /usr/lib

ldconfig /usr/lib

The library is now ready for use. Load up the sdkhelp.htm file with any web browser for detailed information on its use.

Should anyone wish to translate the help files in other languages and send them to me, I would be happy to include them and repackage the tarball.