There is a site that gives access to some files with password provided through sms.
When someone requires a pass he receives an sms with the pass and the same pass is INSERTed in the database.
Then when he logins, the site checks the database for his password and allows entrance or not.
Now what i need is way to disable the ability of 2 or more logins with the same password at the same time.
With a few words i don't want my members to give their passwords to others.