I need to store some sensitive data for a program. For each copy of the program, there will be a unique key for encrypting one (and only one) file using AES encryption (OFB). The key will not be changed (probably forever).
Is it secure if the hash value of the key is used as the IV?
Update: The key is computer generated. The user of the program have no access to the key since it's obtained by the program via secure Web API. The user can only edit a portion of data stored in the file via the program.