McCoy says that Google's security team determined that improving login security would have the most impact on user security. "The user name and password model is fundamentally flawed in several ways," he said in a phone interview.
Gartner VP Avivah Litan says that Google is taking a step in the right direction, though she argues that more needs to be done. "It's better than just passwords," she said in a phone interview.
Two-factor authentication has become popular as a way to give users confidence in cloud computing services, she said, pointing to several recent identity access management acquisitions, such as VMware's acquisition of TriCipher.
"Enterprise customers don't want their accounts being taken over, especially if they're using them to store intellectual property or business plans," she said.
Litan observes that verification codes won't prevent unauthorized access if the user's computer is already compromised by malware like the Zeus trojan and McCoy concedes that point. "It's not a panacea but we do think it's a significant step forward," he said.
Google has already taken a number of such steps to improve online security. In 2004, it added SSL support to Gmail and made SSL the default earlier this year. The company has also made an encrypted version of Google Search available and had taken steps to allow Gmail users to see when and from which IP address their Gmail account was last accessed.
Litan notes that two-factor authentication is no longer enough for many banks and she suggests that Google will have to move on to monitoring for suspicious use patterns. While McCoy declined to provide specifics about Google's future security plans, he points to Gmail's IP address login records as evidence that Google is already moving in the direction that Litan advocates.
"We have to assume there is no security system we can deploy that's bulletproof," he said. "At that point, it makes sense to switch to notification."