Understanding Have I Been Pwned's Use of SHA-1 and k-Anonymity
Four and a half years ago now, I rolled out version 2 of HIBP's Pwned Passwords [https://www.troyhunt.com/ive-just-launched-pwned-passwords-version-2/] that implemented a really cool k-anonymity model courtesy of the brains at Cloudflare. Later in 2018, I did the same thing with the email address search feature [https://www.troyhunt.com/were-baking-have-i-been-pwned-into-firefox-and-1password/] used by Mozilla, 1Password and a handful of other paying subscribers. It works beautifully; it's ridi...