security – Page 18

Client Certificate Authentication

While most HTTPS sites only authenticate the server (using a certificate sent by the website), HTTPS also supports a mutual authentication mode, whereby the client supplies a certificate that authenticates the visiting user’s identity. Such a certificate might be stored on a SmartCard, or used as a part of an OS identity feature like WindowsContinue reading “Client Certificate Authentication”

Browser Password Managers: Threat Models

All major browsers have a built-in password manager. So we should use them, right? I Do Should You? The easy answer is “Yes, use your browser’s password manager!“ The more nuanced answer begins: “Tell me about your threat model?” As when evaluating almost any security feature, my threat model might not match your threat model,Continue reading “Browser Password Managers: Threat Models”

Security Zones in Edge (and Chrome)

Last updated: 25 March 2025 Browsers As Decision Makers As a part of every page load, browsers have to make dozens, hundreds, or even thousands of decisions — should a particular API be available? Should a resource load be permitted? Should script be allowed to run? Should video be allowed to start playing automatically? ShouldContinue reading “Security Zones in Edge (and Chrome)”

Retiring Internet Explorer

Prelude In late 2004, I was the Program Manager for Microsoft’s clipart website, delivering a million pieces of clipart to Microsoft Office customers every day. It was great fun. But there was a problem– our “Clip of the Day” feature, meant to spotlight a new and topical piece of clipart every day, wasn’t changing asContinue reading “Retiring Internet Explorer”

Disabling TLS/1.0 and TLS/1.1 in the new Edge Browser

UPDATE: Timelines in this post were updated in March 2020, October 2020, April 2021, and October 2021 to reflect the best available information. HTTPS traffic is encrypted and protected from snooping and modification by an underlying protocol called Transport Layer Security (TLS). Disabling outdated versions of the TLS security protocol will help move the webContinue reading “Disabling TLS/1.0 and TLS/1.1 in the new Edge Browser”