Posted by Nathan Parker, Varun Khaneja, Eric Mill and Kiran C Nair – Chrome Safe Browsing team

Over the past few years we’ve seen threats on the web becoming increasingly sophisticated. Phishing sites rotate domains very quickly to avoid being blocked, and malware campaigns are directly targeting at-risk users. We’ve realized that to combat these most effectively, security cannot be one-size-fits-all anymore: That’s why today we are announcing Enhanced Safe Browsing protection in Chrome, a new option for users who require or want a more advanced level of security while browsing the web.

Turning on Enhanced Safe Browsing will substantially increase protection from dangerous websites and downloads. By sharing real-time data with Google Safe Browsing, Chrome can proactively protect you against dangerous sites. If you’re signed in, Chrome and other Google apps you use (Gmail, Drive, etc) will be able to provide improved protection based on a holistic view of threats you encounter on the web and attacks against your Google Account. In other words, we’re bringing the intelligence of Google’s cutting-edge security tools directly into your browser.

Over the next year, we’ll be adding even more protections to this mode, including tailored warnings for phishing sites and file downloads and cross-product alerts.

Building upon Safe Browsing

Safe Browsing’s blocklist API is an existing security protocol that protects billions of devices worldwide. Every day, Safe Browsing discovers thousands of new unsafe sites and adds them to the blocklist API that is shared with the web industry. Chrome checks the URL of each site you visit or file you download against a local list, which is updated approximately every 30 minutes. Increasingly, some sophisticated phishing sites slip through that 30-minute refresh window by switching domains very quickly.

This protocol is designed so that Google cannot determine the actual URL Chrome visited from this information, and thus by necessity the same verdict is returned regardless of the user’s situation. This means Chrome can’t adjust protection based on what kinds of threats a particular user is seeing or the type of sites they normally visit. So while the Safe Browsing blocklist API remains very powerful and will continue to protect users, we’ve been looking for ways to provide more proactive and tailored protections.

How Enhanced Safe Browsing works

When you switch to Enhanced Safe Browsing, Chrome will share additional security data directly with Google Safe Browsing to enable more accurate threat assessments. For example, Chrome will check uncommon URLs in real time to detect whether the site you are about to visit may be a phishing site. Chrome will also send a small sample of pages and suspicious downloads to help discover new threats against you and other Chrome users.

If you are signed in to Chrome, this data is temporarily linked to your Google Account. We do this so that when an attack is detected against your browser or account, Safe Browsing can tailor its protections to your situation. In this way, we can provide the most precise protection without unnecessary warnings. After a short period, Safe Browsing anonymizes this data so it is no longer connected to your account.

You can opt in to this mode by visiting Privacy and Security settings > Security > and selecting the “Enhanced protection” mode under Safe Browsing. It will be rolled out gradually in M83 on desktop platforms, with Android support coming in a future release. Enterprise administrators can control this setting via the SafeBrowsingProtectionLevel policy.

Tailored protections

Chrome’s billions of users are incredibly diverse, with a full spectrum of needs and perspectives in security and privacy. We will continue to invest in both Standard and Enhanced Safe Browsing with the goal to expand Chrome’s security offerings to cover all users.