Password checkup: from 0 to 650k users in 20 days

Password checkup allows users to check, in a privacy-preserving manner, whether their username and password matches one of the more than 4B+ credentials exposed by third-party data breaches of which Google is aware. Very early on we converged on Password Checkup’s single purpose: to provide a privacy-preserving protocol for users to learn whether any of their online account credentials are included in a data breach, so they can proactively reset their passwords. Password Checkup’s technical foundation is its innovative protocol that guarantees users that Google will learn nothing about credentials queried by a user.

Source: elie.net