What the heck is this? Optical noise encryption?
Anyone know anything about this? How secure is this? If you have to have 2 "identical" lasers to pull this off, sounds like this would not be very secure, since there must be a pretty wide margin of error (I mean, how "identical" can 2 lasers be?) ____ from EduPage ____ OPEN SECRET Instead of using mathematical codes to scramble and unscramble messages, Georgia Tech physicists are devising a way of sending a message with electronic noise generated by a flickering laser. By connecting identical lasers over fiber optics, the same random pattern of noise is generated at both the sending and receiving end, and the receiving simply subtracts the noise to uncover the message. (Atlanta Journal-Constitution 4/7/94 E2) __ end _______________ -- Stanton McCandlish * mech@eff.org * Electronic Frontier Found. OnlineActivist "In a Time/CNN poll of 1,000 Americans conducted last week by Yankelovich Partners, two-thirds said it was more important to protect the privacy of phone calls than to preserve the ability of police to conduct wiretaps. When informed about the Clipper Chip, 80% said they opposed it." - Philip Elmer-Dewitt, "Who Should Keep the Keys", TIME, Mar. 14 1994
I don't know much about his "optical noise" encryption, but Scientific American ran an article in the Amatuer Scientist column outlining an encryption scheme involved much the same ideas. Their scheme was to find, and digitize a chaotic source as a carrier signal and then add the information to the signal. Decryption involved subracting the source signal from the encoded one. Information encrypted this way would be positively unbreakable by anyone without the chaotic source, as the whole scheme is entirely random. The biggest problem is of course, transmitting the source in a secure manner. It is not enough to know the configuration of the generator of the source, unless you also the _exact_ initial conditions (which are, of course, impossible). One solution to this problem might be to use a recursive equation to generate a source from a small (one-hundred+ digit) seed, and the number of iterations necessary to reproduce the source. The nice thing about this is that the equation could also be customized, something like: x= (k)(x^2)+a, where "a" and "k" are constants that may be altered, thus providing two methods of encryption. This scheme would also be a solution to the problem of the source being corrupted during transmission (which would ruin any attempts to use it). But the equation and the seed would still have to be transmitted somehow. Hmmm.... you could openly send the seed and the encoded information, and then call the reciever to tell them to convert a given sentence into decimal equivalent...etc
Ethan D Schartman says:
One solution to this problem might be to use a recursive equation to generate a source from a small (one-hundred+ digit) seed, and the number of iterations necessary to reproduce the source. The nice thing about this is that the equation could also be customized, something like: x= (k)(x^2)+a, where "a" and "k" are constants that may be
And at this point I've just built an ordinary PRNG+Xor based stream cipher and the usual techniques to break it all apply. All this "encryption with chaos" stuff just adds up to "look at my fancy PRNG", which of course is a game that crypto people have been playing for a long time. I'm starting to get alarm bells go off every time "chaos" is mentioned. Perry
participants (3)
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Ethan D Schartman -
Perry E. Metzger -
Stanton McCandlish