This open source cross platform program will encrypt text messages using a wide range of algorithms to choose from, AES, Blowfish, ARC2, CAST, 3DES or RSA using your own public encryption key, text compression with Zlib or Bz2 can be performed before encryption.
Scramble-Egg has a portable version to take it with you in a USB thumbdrive, needing 20MB of space, the software doesn’t need any administrator rights or special plug ins to run, it is an ideal portable encryption tool, the resulting encrypted text can be saved as XML, Json, UU or a .png image, a “No tags” option can be turned on and off depending on if you want the receiving end to know algorithm combination has been used leaving an attacker intercepting the encrypted message wondering what kind of file it is as it doesn’t have any identifying sign giving away what tool has been used for encryption, in order for someone to decrypt the message, besides the password, they will also need to know the cipher combination, if you eliminate tags you will have to inform the receiver about the used combination.
You can copy the ciphered text and send it by email, paste in a document or post it to a Usenet group, encryption is performed in real time slowing down your computer as you type with the CPU load spiking implementing the encryption algorithm, as soon as you add a character or change some setting you will see the resulting ciphered text straight away on the second pane.
For covert communications you could easily embed a small encrypted text message in a webpage HTML code and in the event that anyone looked at the source code, which few people do, they would not be able to work out what the message says or what has been used to cipher it, the advantage of embedding an encrypted message on a website as opposed to sending it is that if the website has lots of traffic, it becomes impossible to know who received/read it.
The help file is very basic and it could be improved, Scrambled Egg is easy to use but it appears to assume that people using it already understand what each one of the compression and encryption algorithms mean as the instructions do not explain anything about them, I would recommend you use AES for encryption as it is a standard algorithm widely reviewed by cryptographers and regularly tested for weaknesses. My favourite feature is that Scrambled Egg works in Windows, Linux and Mac, this makes it easy for your friends to use this encryption tool regardless of their operating system.