Every time you visit a website, especially one where you enter personal info or buy things, you probably look for a little padlock symbol in your browser. That padlock means the site is secure, and your connection is private. This security relies on something called a digital certificate, which is like an ID card for websites.

These certificates are issued by special companies called Certificate Authorities (CAs). You trust these CAs to make sure websites are who they say they are. But what happens when one of these trusted authorities has problems? That's the unsettling story of e-Tugra, a certificate authority whose security flaws shook the digital world, even if many people never heard about it.