I used to use a similar system (http://crypto.stanford.edu/PwdHash/pwdhash.pdf http://crypto.stanford.edu/PwdHash/pwdhash.pdf), until I realized it has a glarin

I used to use a similar system (http://crypto.stanford.edu/PwdHash/pwdhash.pdf http://crypto.stanford.edu/PwdHash/pwdhash.pdf), until I realized it has a glaring issue when passwords need be rotated. Assume a service you use was breached, and you have to replace your password there. You can work around it by having another input to your generator. Instead of (master password, service), you now have (master password, service, version). Maybe you append the version into one of the other arguments to keep the function the same; doesn't matter: now there's a new, per-service argument you have to track and remember.