In article <[EMAIL PROTECTED]>, Peter Fairbrother <[EMAIL PROTECTED]> wrote: > Get the "pull" from a "party popper" and wrap it in a dollar bill. Record > the serial number of the bill (some crypto here maybe). Make it impossible > to open the closet without setting the "pull" off, ie no trapdoor. > > Fairly good tamper-evidence, and the token is hard (and very illegal!) to > forge.
Most of the security features of a dollar bill are not directed toward the serial number; they are designed to prevent changing the denomination, or to increase the cost of creating a real-looking bill from scratch. Changing the serial number is likely to be fairly straightforward. For this to be secure, you would have to keep the serial number a secret; and in that case, the paper could be any piece of paper with a secret written on it. > Depends on your threat model, of course. But of course. -- Shields.
