Ajax Secure Service Layer is an open source library built to substitute the need for SSL in Ajax applications.First a random 128-bit key is negotiated with the server, then, once the connection is established, data is exchanged using BlockTEA.aSSL is composed of some Javascript files and a server side component.
More about aSSL,its working and downloads, Visit :Ajax Secure Service Layer
Future developments will see aSSL move away from DES and towards AES encryption.