Yahoo and Cisco have joined hands in the development of the e-mail authentication specification, called DomainKeys Identified Mail (DKIM) and now they are submitting it to the Internet Engineering Task Force (IETF) to be considered as an industry standard.

The technology attaches digital signatures to mail, which then can be checked to ensure that the message was actually sent from the domain in the sender's address.

Spammers use spoofing to change an e-mail message's header information to deceive recipients into believing the message was sent by a known and trusted personal acquaintance or a legitimate business, such as a bank or an online store.

DKIM is designed to be to be as compatible as possible with DomainKeys, so that migration to DKIM will be smooth for organizations that have already implemented DomainKeys, said Jim Fenton, a Distinguished Engineer at Cisco.

"We have made a real effort to preserve the investment in infrastructure that people who have implemented DomainKeys have made," Fenton said.

The companies decided to combine their cryptographic technologies because they found them to be very similar and "we didn't feel we needed to have two technologies that did the same thing," Fenton said.