Ya, the first time I heard of it I had the same reaction, but it's legitimate.
https://en.wikipedia.org/wiki/Secure_Remote_Password_protoco... That page is quite old, but lots of bodies use it: http://srp.stanford.edu/links.html
Amazon uses it in a service: https://docs.aws.amazon.com/cognito/latest/developerguide/am...
Also, as another commenter said, Apple uses it in Homekit.