Holograms are famously hard to duplicate. Here is a scheme to use a hologram in an ID card.
- Using film, make a hologram of the employee’s bust, with company logo in the shot.
- Make an ordinary color photo as well.
- Embed the holographic negative in the ID (possibly laminating it.)
- On the card, print the photo, the name, employee number, corporate logo etc.
- 3-D bar code a salted hash of the data, salted with salt “K”
To verify the ID, the gate-keeper must:
- Visually compare the photograph to the individual
- Using a laser pointer, or possibly a grocery store type mirror based LED projector, view the hologram, comparing it to BOTH the individual AND the photograph.
- Type ALL identifying data into a computer form, which performs a salted hash (salted with salt “P”) of the data, and performs an RSA signature associated with the authorized access point.
- Scan 3-D bar code hash.
- Using the Corporate RSA Public key, send signed info to escrow system for authentication.
- At key escrow system compare “P” salted hash to record of authorized users, and ensure that “K” salted hash also hashes to the correct “P” salted second value (hashing the hash.) This ensures that dummy employee numbers etc, are compared in two ways.
- Receive (in this example) authorization #, time and date stamped, RSA encrypted with public key of the authorized access point.
- De-crypt and authorize to proceed.
While this might seem cumbersome, it would be very difficult to deceive. It would also accommodate environments in which the gate-keeper did not recognize the employee personally. It would be somewhat slow, and it might be possible to improve it without compromise – this is a nascent idea.