TSS OfficeLock is a data security plug-in for Microsoft Office 95, 97 and 2000. OfficeLock integrates into Office to automatically protect your Office files from being opened, changed or infected. It actually stays with your files wherever they go, preventing unauthorized users from opening, changing, or infecting your Word documents, Excel spreadsheets, Access databases or PowerPoint presentations. OfficeLock automatically decrypts files when opened and encrypts them again when they're closed. It uses the unbreakable PGP data encryption engine.