Niether the User Registration Solution Pack or PowerStore make use of sha1 encryption for the passwords, the user registration setup on both of these is very similar. If you would like to update the update the PowerStore or URSP you would need to make use of SecurityAssist to do so. If you have done any customizations to PowerStore already you will know that it can be tricky at times and you should work on backups of the pages first and test them to ensure that all is working correctly before implementing them into your live site.