Chrome’s HTTP cache keying scheme will be updated to include an “is-cross-site-main-frame-navigation” boolean to mitigate cross-site leak attacks involving top-level navigation. Specifically, this will prevent cross-site attacks in which an attacker can initiate a top-level navigation to a given page and then navigate to a resource known to be loaded by the page in order to infer sensitive information via load timing. This change also improves privacy by preventing a malicious site from using navigations to infer whether a user has visited a given site previously.