HIBP (Have I Been Pwned) is a data breach search engine. You may search with your email or password to see if your personal data has been published online.

Founded in 2013, HIBP has grown substantially and even has organizations such as the FBI providing them compromised data.

HIBP has an API and notification service for receiving a notice if your info has been posted.

Cloudflare partnered with HIBP to use K-anonymity for the password search. Doing so, your full password doesn't need to be sent to the server to check if it's been in a breach. The hashed passwords' prefix is sent rather, and the client does the rest of the work.
Person - "I've been getting security notice emails/other sus events"
Person's friend - "Check if you've been breached on Have I Been Pwned, good chance you're on there!"
by mak0001 September 8, 2021
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