In this case, the security is provided by these companies. This particular option will not be considered further in this paper. At no stage is the transaction decrypted whilst it travels over the Internet, or whilst it is stored on a web site. Hence there is no large store of orders available online to invite attack. The encryption is carried out by using a Java applet.
Decryption is carried out on the vendor's PC after orders have been downloaded from the web.
The encryption technique used falls into two parts. The Diffie-Hellman key currently used is 256 bits and this will be increased further in the future up to 1024 bits, depending on performance. Where the SSL option is used, the buyers personal details, credit card information and other order information is sent from the browser to the server, using industry standard SSL encryption. At the server, the order is encrypted before being written to disk using the same method and encrypting the same fields as is explained in the Java encryption. Hence the order is only stored encrypted on the web site.