We had moved one of our store from PrestaShop to nopCommerce. During the migration, we lost all registered customer's passwords because of PrestaShop password encryption policy. I don't think so, we will be able to recover existing passwords.
We have migrated all customers and given them a default password. We were thinking if there is a way to force each customer to change the password on the first-time login. Like, system force customer to change password on first login attempt.