At 12:26 07/28/96 +0200, Remo Pini wrote:
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To: cypherpunks@toad.com Date: Sun Jul 28 12:24:57 1996
Even if they did change the frequency the call was on, it would be a simple matter to decode how the frequency change was negotiated, and "follow" the call (also easily accomplished with cellular calls). Failing that, there is a very limited range of frequencies allocated for cordless fones, and simply re-scanning for the conversation is a trivial inconvenience. //cerridwyn//
Most of those systems do also change the order of the transmitted data, and that's not limited to a few possibilities. If it's digital, they usually encrypt it (only weak, but hey, you normally have to find the key real time!)
The key doesn't need to be found in real time! You can always record the call and decrypt it later. If the information deals with an event in the future, you could have plenty of time to crack it.
G.C.G.