Browser SSO / Automatic Signin

Last Update: 8 March 2024 Over the years, I’ve written a bunch about authentication in browsers, and today I aim to shed some light on another authentication feature that is not super-well understood: Browser SSO. Recently, a user expressed surprise that after using the browser’s “Clear browsing data” option to delete everything, when they revisitedContinue reading “Browser SSO / Automatic Signin”

Improving the Microsoft Defender Browser Protection Extension

Earlier this year, I wrote about various extensions available to bolster your browser’s defenses against malicious sites. Today, let’s look at another such extension: the Microsoft Defender Browser Protection extension. I first helped out with extension back in 2018 when I was an engineer on the Chrome Security team, and this spring, I was taskedContinue reading “Improving the Microsoft Defender Browser Protection Extension”

How do Random Credentials Mysteriously Appear?

One commonly-reported issue to browsers’ security teams sounds like: “Some random person’s passwords started appearing in my browser password manager?!? This must be a security bug of some sort!” This issue has been reported dozens of times, and it’s a reflection of a perhaps-surprising behavior of browser login and sync. So, what’s happening? Background EvenContinue reading “How do Random Credentials Mysteriously Appear?”

New TLDs: Not Bad, Actually

The Top Level Domain (TLD) is the final label in a fully-qualified domain name: The most common TLD you’ll see is com, but you may be surprised to learn that there are 1479 registered TLDs today. This list can be subdivided into categories: Some TLD owners will rent domain names under the TLD to anyContinue reading “New TLDs: Not Bad, Actually”

(The Futility of) Keeping Secrets from Yourself

Many interesting problems in software design boil down to “I need my client application to know a secret, but I don’t want the user of that application (or malware) to be able to learn that secret.“ Some examples include: …and likely others. In general, if your design relies on having a client protect a secretContinue reading “(The Futility of) Keeping Secrets from Yourself”