One Time Pad for you!
OTP4U is a tool that allows users to easily exchange a random key between them and then use it as a key for a One Time Pad cipher (if the key comes from a true random number generator, the One Time Pad is an unbreakable cipher). Since version 0.9.3 a CSPRNG (Cryptographically Secure Pseudo Random Number Generator) is used to generate the keys of the cipher.
See how it works.
OTP4U is an open project and is under development: if you want to participate, here are some things to do: developing the GUI, adding a CSPRNG (possibly an existing one), improving the performance. If you are interested, or have any proposal, please contact me. Send your bug report here.
If you'd like to implement an open source version of the OTP4U algorithm in a language different from Java, please send it to me! I'll publish it here.
Take a look at Sysepub : it gave me the idea for OTP4U
Note: OTP4U is NOT a well known and established cipher, but rather a proposal. If you want, read a public discussion about it, that took place on the Usenet (January 2003).
Please note also that OTP4U comes with the GNU GPL license, then WITHOUT ANY WARRANTY of any kind.