From my conversation with the receptionist on the other end of the phone, which was somewhat less than informative, the idea of Spread Spectrum technology is that the signal is spread out into individual packets on different wavelengths,
Excerpted from "Wired," August 1993 Playboy (Not THAT Wired) Reprinted without Permission Spread Spectrum technology was developed for the military to allow for high-security communications with crystal-clear reception. Now Cincinatti Microwave has introduced the Escort 9000 ($400), a cordless digital phone with Spread Spectrum that operates on the recently approved 900 MHz radio frequency (that's 20 times higher than the frequency conventional cordless phones use). This marriage of technologies gives the Escort 9000 a remarkable range of about a half maile, superior reception and complete privacy. "Previous attempts to bring Spread Spectrum to the consumer market have been too costly and too bulky for personal use," said Cincinatti Microwave president Jacques Robinson, who sells the phones directly to the public. (Call 800-433-3487 for more information or to order one.) Another company, Cobra, incorporates CM's Spread Spectrum technology into its latest 900 MHz model, and AT & T will introduce a 900 MHz Spread Spectrum phone in the fall. Tropez and Panasonic also offer 900 MHz phones (without Spread Spectrum). It is rumored that the range for some 900 MHz phones could be increased in the future to up to seven miles, which means that one could serve as an around-town alternative to a cellular phone. ---END EXCERPT Now, here's my problem with this nice-sounding product. I called the 800 number to ask for an explanation of this product, which immediately aroused my suspicion. then reconstituted at the other end, using some sort of session key generated at the beginning of each transaction. Considering the rather lax security of high-ranking government and military officials with phone technology, recent eavesdropping on Air Force One and the White House most glaringly, I find it difficult to accept as kosher any security scheme created by the government and then offered to private industry. More chillingly, the receptionist told me that no one would be able to perform surveillance on me "except the government." Alerted to this possibility, I immediately asked whether it had the Clipper Chip or the Capstone, or whether there was some sort of key escrow involved. This got me put on hold for a couple minutes. Then the receptionist returned, and told me that the person from the engineering department who took care of the phones had indicated that not even the government had the technology to monitor these phones. Upon asking how and why the government might do this, I received a rather chilly notification that the engineering department, was, of course, unwilling to reveal these secrets. Well, it was worth a try. I gave them my address so that they could send me further information. More reports forthcoming. You can contact Cincinatti Microwave by telephone at: (800) 433-3487 or by snailmail at: Cincinatti Microwave 1 Microwave Plaza Cincinatti, OH 45249 ---- -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.3a mQCNAiyKoFQAAAEEAL22Al/Xil0UER1V7AlS4+eJmOQ6ruIojmq1XCSE7mCqLw3Q ILHBGlcCOl9S20N/8gdge2PfMS9BK794P2r/J3GUjwZw/emKuVm9SXDBpXfdgWax 7jdAGfohRthw/q1+x/z5nJ7gP2C7AZSlsa+XCYYRZbTR2fpaLXzs8jiGc9glAAUT tClSb2JlcnQgVy4gRi4gQ2xhcmsgPHJjbGFya0BueXguY3MuZHUuZWR1Pg== =vJ53 -----END PGP PUBLIC KEY BLOCK-----
"Spread spectrum" does *not* imply "encrypted". The spreading sequences are quite often just simple linear feedback shift registers, which anyone with basic knowledge of cryptanalysis knows how to crack. Anyone with knowledge of the signal format and the right hardware could easily intercept such a signal. This *definitely* includes the government. The fact that spread spectrum usually thwarts the average scanner enthusiast is actually rather unfortunate in my opinion, because that lessens the demand for truely secure cryptography. Phil
Now, here's my problem with this nice-sounding product. I called the 800 number to ask for an explanation of this product, which immediately aroused my suspicion.
From my conversation with the receptionist on the other end of the phone, which was somewhat less than informative, the idea of Spread Spectrum technology is that the signal is spread out into individual packets on different wavelengths, then reconstituted at the other end, using some sort of session key generated at the beginning of each transaction.
Essentially this is correct, but as Phil Karn already pointed out... spread spectrum is easy to de-spread. However, Motorola has a cordless phone called the Secure Clear phone that operates at 46 to 50 MHz (standard cordless phone freqs.) that has "encryption" between the handset and the base. After calling motorola I am not impressed... they use frequency inversion. Their support person stated that the goal is to "stop casual eavesdroppers that might use baby-monitors or police scanners." Which is fine and good. I know, from personal experience, the problems that can arise from cordless telephones being monitored and the information used against a person. The Motorola and Cincinatti Microwave phones can help with the casual listeners that are out there (and there are quite a few of them!), but neither will stop an interested party with resources to spare. :) -- "I'm not being irrational, I just know to much." - Tim Allen -- Pat Hykkonen, N5NPL Texas State Technical College at Waco Internet: {pat,postmaster,root}@tstc.edu Instructional Network Services Packet: N5NPL@WD5KAL.#CENTX.TX.USA.NA 3801 Campus Dr. Waco, Tx 76705 Public keys available! ** 1984 + 10 ** V:(817) 867-4830 F:(817) 799-2843
participants (3)
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Clark Reynard
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karn@qualcomm.com
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pat@tstc.edu