Description

Google is introducing new user protection features to Chrome with Device Bound Session Credentials (DBSC), aimed at combatting cookie theft by binding browser authentication sessions to devices. Developed by the Web Incubator Community Group (WICG) and expected to become an open standard, DBSC employs private key authentication to secure user sessions. While cookies enhance browsing experience, they are vulnerable to theft and can compromise web accounts if stolen, particularly authentication cookies used post-login. Traditional methods of cookie harvesting via malware can bypass browser defenses, allowing stolen cookies to be used even after malware removal. DBSC addresses this by associating each session with a pair of public and private keys stored securely on the device, making local detection and cleanup more effective against cookie theft malware. DBSC provides websites with an API to manage key lifetimes and check for proof of possession. Each session generates its own private key, ensuring session isolation. The protocol, triggered at sign-in, instructs the browser to verify certain cookies' presence for active sessions, holding network requests if cookies are absent while querying for updates. Google assures that DBSC does not leak device information to servers; only the per-session public key is transmitted for later key possession certification. Its deployment in Chrome will be based on device hardware capabilities, with consideration for software key support. DBSC's rollout aligns with third-party cookie phase-out, with measures to prevent it from becoming a new tracking vector. A DBSC prototype is being tested on Google Accounts in Chrome Beta, with full deployment expected to enhance both consumer and enterprise account security. Origin trials for websites are slated for late 2024, with plans to integrate DBSC into Google Workspace and Google Cloud for additional account protection.