PC Floppy Copy Protection: Vault Prolok
Summary
This article covers Vault Corporation's Prolok floppy copy protection, detailing how three fingerprint areas on disks created a writable-destroyable protection mechanism, the protected loader on the PROLOK.EXE utility, and the business and legal battles surrounding Prolok (including Vault vs Quaid Software and the backup rights case). It also surveys related Vault products (Hard Disk Prolok, Filelok, Telelok, Techline), industry fallout, and modern emulation efforts to preserve Prolok's history.