I will first describe how my site stores user information. Every personal information is first hashed by `Sha1`. The hashed string is then subtracted by `substr($var, 2, 38)` and then stored.

This includes all information on my website (email addresses used for login and password resets, passwords, IP addresses) except comments, which are stored in plain text.

Is this enough to consider my users anonymized (to me and to everyone else) even though they are registered under bits of strings that look like a set of random numbers and characters? Or is it still pseudonymization?

If so, what can I do to make users anonymous but still registered (required to login)? Is it even possible?