Microsoft has publicly criticised Google Chrome's privacy.
Internet Explorer security general manager Amy Barzdukas used London's RSA conference to put its rival's Omnibox in a negative light.
Barzdukas noted that in Internet Explorer 8's default setting, it kept the address box and search box completely separate for privacy reasons.
"The address box is optimised for you, the individual user," she said. "It's optimised to get the user to the sites that you go [to] over and over again your favourites and your bookmarked sites."
"The search box is optimised for a very different reason," she added. "They are kept separate for privacy."
Because of this, when a user types a URL into Internet Explorer's address box, no information goes back to Microsoft, she claimed.
Barzdukas then demonstrated what happened when a user typed something into Google Chrome's Omnibox, which acts as both a search tool and an address bar.
"If you type in that Omnibox, every keystroke that you type is sending a packet to Google," she said.
She said that users may not be aware of the trade off or even care about it, but Microsoft believed that browser vendors needed to be careful about privacy no matter what.
The attack on the Google Chrome browser comes nearly a month after the furore over a Google Chrome plugin for Internet Explorer that Microsoft claimed was a security risk and would not trust with their "friends and families".
