Talk:SIGSALY
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Stimulus
- James Ellis' non-secret encryption for which SIGSALY or something simliar seems to have been the stimulus
Do we have any evidence that Ellis was motivated by SIGSALY? — Matt 12:17, 22 Jun 2004 (UTC)
Duplicate article
Blast! I've just spent a day writing an article on the "X System", as my reference book (see 'Further reading' I just added) calls it, only to discover that we already have an article on this topic, just one which wasn't listed under all its names.
Which raises the question of what we ought to call the article. Both the Bell book, and the Turing bio by Hodges, which also covers it in some detail, call it the "X System" (or some typographical variant thereof, such as "X-system"). Do we want to leave it here (which is, I gather, the name the NSA museum has it under), or use the one in all the references? Noel (talk) 19:25, 6 Mar 2005 (UTC)
- Sorry to hear about your reduplication of effort, although you've appear to have merged in a lot good stuff into this article regardless — nice work! Regarding the name: I don't have strong feelings either way, but a few minutes with Google suggests that SIGSALY is the more common name on the Web. — Matt Crypto 01:09, 8 Mar 2005 (UTC)
Spread spectrum
I don't see how this system was a spread-spectrum system. To me, SS implies that the signal is spread out across a wide frequency range so as to be imprevious to narrow-band jamming. It's true that the transmission technique used by this system was relatively good against atmospheric distortion (natural "jamming", as it were), but I would describe it more as a "frequency modulation" system, rather than SS. They used FM because an amplitude modulated signal wouldn't give the required S/N (the vocoded signals needed to be reproduced +- 10% in amplitude for the unvocoded speech to be intelligible), and there was too much fading on long hops to meet this target if they used AM. After all, I don't think anyone would describe ordinary FM commercial radio as SS! Noel (talk) 23:02, 6 Mar 2005 (UTC)
- I'm out of my depth technically, but perhaps we could directly attribute the claim to Bennett's IEEE article? That is, something like "Bennett (1983) suggests that SIGSALY can be thought of as being one of the very first successful applications of spread spectrum technology".— Matt Crypto 01:09, 8 Mar 2005 (UTC)