A method and system for reducing unauthorized software use include generating a key based on computer-specific information of a computer on which the software is installed and using the key to encrypt an authorization code which enables use of the software on the computer. A representative maintains contact with the software user as a new authorization code from the representative is required after some period of use of the software. The representative encrypts the new password using the key and transfers the encrypted key to authorize use of the software for a next period of use. The encrypted password is a form of digital signature or certificate which is unique to a particular computer and limits use of the software to the particular computer. The key may be generated using various computer-specific information such as the motherboard/processor identification, the number of bad sectors or hard disk identification, and/or the amount of installed memory.