According to Nigel Hawthorne, managing director at network caching specialist Cacheflow, encryption using SSL software could be slowing down Web servers by a factor of 10.
Security is a major concern for e-commerce ventures, especially financial institutions, and problems at both Abbey National spin-off Cahoot and Halifax's IF (Intelligent Finance) hinged on performance issues during times of peak load.
"These, and other banking sites, usually use SSL-encrypted data throughout their sites to ensure the security of their customers' financial information," Hawthorne explained, "The additional burden of generating and checking SSL keys usually reduces the number of simultaneous users that a Web server can support by a factor of 10,"
Cahoot has not detailed the cause of its technical hitch, which stopped thousands of users signing up for its new online account, and IF, whose network suffered overload during testing, has also refused to comment on its difficulties.
Chris Christiansen, programme director for Internet security at market research company IDC, agreed that encryption needs to be considered when planning a commercial Web site.
"We're finally seeing real-world examples of server-based SSL software failing to meet the financial community's requirements - namely, failing to scale. Turning to hardware-based encryption is more than just a quick fix, it is a strategic solution," he said.
"These appliances may be hard-wired but they are still flexible enough to accept today's PKI [public key infrastructure] or SSL solutions, while able to accommodate future encryption algorithms."
SSL appliances are widely available but Cacheflow said its SSL acceleration hardware is the first to embed the technology in a caching product.