When a user is created in Linux, their username can be seen publicly in the
passwd file. Is there a hash set for that?
yes, the user name is visible publicly. You can pick a pseudonym if you like, but the name has to be unique, and will be visible to the other users
In addition to what @gilles has already stated. The primary key, unique identifier of a user is the
to create another user that's effectively the same you could add
which has the same
The password is hashed, but what type of hash is defined by pam configuration, in my case I'm using sha512.