When I was searching for a password manager to use I stumbled upon the concept of Master Password which instead of encrypting and saving your passwords, generates them by using your master password and the name of the service/website you use it for. This way your passwords don't have to be stored anywhere since they are generated every time you enter your master password in the app. I liked this concept but I wanted to try making my own app for this.
So what I thought of is basically:
- get master password and service url from the user
- add the strings together
- create a hash of this string using SHA-512
- use this hash as the seed for a PRNG that generates the password
Now my question: If you use a good master password, would there be any security risks concerning this concept?