Secure SSL Certificate Encryption Strength
(copied from the secure server site: godaddy.com and Wikipedia)
All of our Secure Sockets Layer (SSL) Certificates enable you to protect transactions and other activity on your Web site with as much as AES 256-bit Secure Sockets Layer (SSL) encryption. All you need to enable this high-grade encryption level is a Linux-based hosting plan and an SSL certificate for your site.
The actual encryption strength on a secure Web site connection enabled by a digital SSL certificate is determined by the level of encryption supported by the site visitor's browser and the server that the Web site resides on. For example, the combination of a Firefox browser and an Apache Web server enables 256-bit AES encryption with our SSL certificates. That means that if your Web site is hosted on a server whose software supports 256-bit encryption such as Apache, then site visitors that use a Firefox browser will have their transactions with your site protected by 256-encryption. Thus with the right combination of Web browser and Web server, you can establish a 256-bit encrypted secure connection via an SSL certificate.
Encryption strength is measured in key length — number of bits in the key. To decipher an SSL communication, one needs to generate the correct decoding key. AES permits the use of 256 bit keys. A 256 bit key requires not merely twice as long to crack as a 128 bit key, but rather 2128 times as long. If a device could be built that would crack a billion billion (1018) AES keys per second, it would require 3,671,743,063,080,802,746,815,416,825,491,118,336,290,905,145,409,708 years to exhaust the 256 bit key space.
It should therefore be clear that, generally speaking, 128 bit keys are impractical to attack by brute force methods using current technology and resources, and that 256 bit keys are not likely to be broken by brute force methods using any obvious future technology.