How to transfer user accounts from old system to new one ?

[adrianmak]

A client want to develop a new service booking system to replace the old one (php).

It's not that difficult to develop it , but the key is how to transfer/import user account from the old system ?

Each account has a password field and it's encrypted.

[LostKobrakai]

Easiest: Implement a password forgotten process and let users use this one to update/change their password on the new system

Otherwise: Implement the old system's password comparison and use it to compare it to the submitted password. There are various threads about hooking into the login process of processwire. 

[kixe]

Export/ Import your database and use the same User Authentication Salt from config.php.

$config->userAuthSalt = 'xxxxxxxxxxxxxx';