"Practical Secret Protection" - читать интересную книгу автора (T T T, M M M, O'Toole Laurence)

2 Active Secret Protection

Let us consider the standard scenario and our basic method of secure communication: Alice wants to send a secret message to Bob while a third party, Eve, wishes to eavesdrop this message. To implement "Rubber-Hose Cryptography" Alice simply kills Eve and sends the message in clear. Note that this renders the method mentioned by Beynon [1] useless. Even assuming the process is completely automated, and the information is extracted from Alice or Bob, this information will never get back to Eve (assuming some rather definitive properties on the nature of the afterlife). Also, there is no need for a cryptographic key of any kind, or indeed any encryption algorithm at all, which significantly reduces the number of operations required (to 1) and consequently the implementation time. We call our system "Practical Secret Protection", or PSP for short.

This is a rather simplified view of things, as there will most likely be more than one person who will try to find out the secret. The level of protection provided by PSP can be increased to the level necessary for specific cases. It may be necessary for Alice to delete[1] all of Eve's associates, employers and likely replacements. It should be noted that the number of operations this system has to perform only grows linearly with the number of eavesdroppers (i.e. the two values are equal). Unfortunately, a major problem with this scheme is that Alice can only operate on known eavesdroppers. There is a way around this though, to be demonstrated in following Section.