The leaks · 76 / 127 · 2 min

Lookalike domains

A domain can use letters that look like the real ones. The bookmark you made is the address. The search result may not be.

A worked case

Someone searches the exchange and clicks the first result. The name is one character off. The certificate is valid for that wrong name. The site asks for a login, then a seed. The bookmark from last month would not have asked.

The letters

Two names can look the same in a browser and be different sites. One letter, or a letter from another alphabet, is enough.

The ad

A paid result can sit above the site you wanted. The padlock means there is a certificate. It does not mean you are at the firm.

The letter from another alphabet

Internationalised domain names can use characters that look like Latin letters and are not. Browsers have spent years deciding when to show the real letters and when to show the disguise. A padlock only means a certificate was issued for the name you are actually on.

The address you typed last month, saved as a bookmark, does not pass through a search ad or a lookalike. The ad and the lookalike do.

Read it yourself

• IDN homograph attack

These links are the record. They are not a recommendation, and they are not instructions. A news story or a court paper can still be wrong about a detail. The check does not change because a famous name is in the story.

Apply the check

Open a question. The line is about this topic. It is not a verdict that anything is safe.

Check yourself

Write it in your own words. The course's answer opens after that. Nothing is sent.