| 摘要 |
<p>A multi-level security system prevents unauthorized use of a computer. The system has a key device carrying a first serial number, a mass storage device installed in the computer and storing a validation record, the validation record having a copy of the first serial number. The computer is automatically powered down if the first serial number and the copy of the first serial number do not match. Also the key device may carry an encryption key. The computer has a device to store a copy of a second serial number. The validation record has an encrypted portion, the encrypted portion carrying an encrypted copy of the second serial number. The computer is automatically powered down if the copy of the second serial number and a decrypted copy of the second serial number do not match. Also, the validation record may carry a personal identification number (validation record PIN). A user to enters an entered version of a PIN (entered PIN). The computer is automatically powered down if the validation PIN and the entered PIN do not match. The key device may carry an access code (key device access code). The validation record has a copy of the access code (validation access code). The validation access code is written to the key device, the key device having means for comparing the key device access code to the validation access code. The computer is powered down if the key device access code and the validation access code do not match. Any combination of a subset of these security measures may be used.</p> |
