UsbKey - program for blocking PC by USB.
If the PC is locked and waiting to log in to the session, and it does not have a special USB-key with the key, then when you log in to the session, it is locked again.
Key - is the bytes.
Key contains:
- 16 bytes - md5(your data)
- 16 random bytes
Yes. The key only needs 32 bytes of memory.
Yes. Just use 1 usb.key file in all PC (You can copy this file from USB).