craig@pyuxv.UUCP (10/26/85)
***Speak up, my surveillance device can't hear you clearly***
The Friday, October 25, 1985 Communications Daily reports that the
US Office of Technology Assessment has issued a report holding that
cellular and cordless telephone calls and other forms of new
communication devices are not sufficiently protected under the 1968
wiretap law. Congress has a measure under consideration that would
strengthen such privacy law requirements extending protection to
cellular and cordless telephones. Markup is expected, for both the
House and Senate versions of the bill, by early next year. There is a
possibility of enactment by the end of 1986.
With regard to wiretapping, USA Today says that 35 federal agencies
use, or have plans to use, new electronic surveillance equipment
that is not controlled by the 1968 law. The article further reports
that domestic US agencies have 288 million files on 114 million people
and that computerized recording devices could improperly monitor
innocent citizens.
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..!ihnp4!pyuxv!craig (RB Craig @ Bell Communications Research)
Piscataway, NJ 08854-1300
If you don't like the world as it is
you may need to learn to like more things.
--
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..!ihnp4!pyuxv!craig (RB Craig @ Bell Communications Research)
Piscataway, NJ 08854-1300
Technology... wouldn't that cork your bobber?karn@petrus.UUCP (Phil R. Karn) (10/27/85)
> Congress has a measure under consideration that would > strengthen such privacy law requirements extending protection to > cellular and cordless telephones. I see this as a very unfortunate development. Once again, the lawyer types think they can simply wish away a problem with an unenforceable law. Has anybody told them that cordless telephones can be intercepted with any cheap AM radio? Or that under the proper circumstances cellular phone conversations can be overheard with an ordinary UHF TV set? Naturally, one major effect of such a law would be to hassle us hams. No doubt there'd be an effort to ban the sale of general coverage receivers (either of the traditional HF type or the new VHF/UHF types like the Yaesu FRG-9600 or the Icom R-7000). Bad guys still intent on monitoring cellular phone would still be able to build their own receive converters with little trouble, and unless we repeal the 4th amendment and allow arbitrary police-state searches of private residences for listening gear, the law won't stop them. Worse, the mere existence of the law will give the users of cordless and cellular phones a false sense of privacy, and nothing is more dangerous when dealing with communications security. The cellular radio operators should be required to inform their customers that their conversations can be overheard (as cordless phone users already are). Customers should be made to understand that they are responsible for their own communications security and encouraged to obtain voice scrambling devices should they wish greater privacy. I see no practical alternative. Phil
die@hydra.UUCP (Dave Emery) (10/31/85)
In article <154@pyuxv.UUCP> craig@pyuxv.UUCP writes: > Congress has a measure under consideration that would >strengthen such privacy law requirements extending protection to >cellular and cordless telephones. Markup is expected, for both the >House and Senate versions of the bill, by early next year. There is a >possibility of enactment by the end of 1986. I have always wondered why the cellular radio standard didn't include digital transmission under (optional?) encryption. Digital transmission would make cellular signals difficult to intercept with scanners or even TV sets, and the hardware required - much like a descrambler for a broadcast tv signal - would be specialized enough so random members of the general public couldn't legally acquire it on the pretext of using it for some legitmate purpose (unlike TVRO's and SSB receivers !!). For a few dollars more the system could supply DES with reasonable key security that would make the cellular link at least as private as the rest of the telephone system. The current transmission method for cellular phones is FM, and the channel spacing is such that there would be plenty of room for a 16 or 32 khz QPSK (or even diphase) adaptive slope (ADPCM) or CSVD transmission of high quality voice. As for performance, I have read some claims that clever demodulators can do as well demodulating digital voice signals near threshold as nbFM. It seems a shame that the designers of a system as sophisticated as the cellular phone system chose not to consider the security issue seriously. I beleive that most of the design work was done in the late 70's when DES chips and LSI PCM chips were at least beginning to appear on the market, certainly any far sighted system architect could have confidently predicted that the required digital hardware would soon be available and eventually be quite cheap. My guess is that low cost in the short term and reduced technological risk dominated their thinking. Perhaps someone on the net can shed some light on why the current fm based system was chosen. The real tragedy is that the proliferation of the current generation of FM based hardware will make it very difficult to convert the whole system over to digital. Perhaps the present transmission sites can be equiped with dual mode radios that would allow subscribers to use digital transmission as an option and thus allow those who understand the risk and want to protect their privacy to enjoy the conveniance and flexibility of roaming cellular phones with a modicum of privacy too. I should think that there might be quite a market for such a higher privacy (and price no doubt) service as people begin to discover that 900 mhz scanners (and some tv sets as Bob Parnass points out) can pick up their fm conversations clearly. Unfortunately, though the NSA has been very active in trying to raise consciousness about security, the more political FCC has yet to authorize secure digital transmission over the current 900 mhz cellular phone frequencies. One would think that the government would get its act together and lead on the issue for once by requiring that all cellular systems be equiped with dual mode capability by some future date. The cost of digital base station transcievers at cell sites and of the required microprocessor systems for key management would be a reasonably small addition to the cost of all the required hardware at cell sites. I suspect that by charging more for a secure service the costs could be recovered (I might add that the systems in the Boston area use microwave links to tie the cells together and those ought to be secured too...). And the digital hardware for mobiles could be implemented in a small number of VLSI chips that ought not to add excessive cost, power consumption or weight to these high tech transceivers. David I. Emery Charles River Data Systems 617-626-1102 983 Concord St., Framingham, MA 01701. uucp: decvax!frog!die
newton2@ucbtopaz.BERKELEY.EDU (11/19/85)
It astonishes me how often the brash assertiveness of a posting scales inversely with the knowledge and authority of the poster. Comes now Larry Lippman, who says cellular speech encryption could never work because a huge database of key pairs would have to include every possible user/transaction. And don't try passing keys before each transaction-- he's thought of that! Has he heard of Diffie and Hellman? Shamir, Rivest and Adleman? Oh.... Never mind.... Doug Maisel
larry@kitty.UUCP (Larry Lippman) (11/24/85)
> > Congress has a measure under consideration that would > >strengthen such privacy law requirements extending protection to > >cellular and cordless telephones. Markup is expected, for both the > >House and Senate versions of the bill, by early next year. There is a > >possibility of enactment by the end of 1986. > I have always wondered why the cellular radio standard didn't > include digital transmission under (optional?) encryption. Digital > transmission would make cellular signals difficult to intercept with > ... Digital speech encoding was not used in the cellular telephone concept for reasons of practicability including, but not limited to: 1. The cellular telephone design concept was considered to provide sufficient security to deter the casual listener using consumer-grade `scanners', antennas, etc. No attempt was even considered to deter a `serious' listener who could spend many thousands of dollars for antenna towers, sophisticated receiving equipment, etc. 2. The cellular telephone concept was intended to be LOW cost and be capable of independent multi-vendor support. Therefore, hardware had to be as simple as possible without employing any one vendor's proprietary technology. While Motorola pretty much developed the cellular concept, they never did it from the standpoint of monopolizing the cellular market - such a monopoly never getting cellular telephones off the ground. While Motorola has also pioneered digital speech encryption using CVSD modulation in their DVP radio systems, this was mostly proprietary technology which Motorola was hardly going to share with the world. 3. Had a digital encryption circuit been used as part of the cellular concept, there is NO practicable way for such a circuit to be kept out of the public's hands. There are at present at least 10 active vendors who manufacture cellular telephone apparatus, and no doubt there will be more. Any `potential' vendor would have to be given encryption circuit details and be sold any integrated circuits designed for this purpose. 4. Had a digital encryption scheme been used so that each cellular telephone had individual encryption keys, EACH receiving and trans- mitting site would have had to have a full database containing a unique cellular telephone identifier number and an encryption key. This same database would have to exist for hundreds and even thousands of sites - and be UPDATED. THIS is probably the single most important reason why encryption is not practicable at this time using the present cellular concept. (It would rather defeat the purpose of encryption if, say, the encryption key were transmitted in the clear prior to start of voice transmission, in case anyone thinks this is would eliminate a database requirement.) 5. Radio transmission is full-duplex, so that a monitor receiver would be able to hear only one side of the transmission. (Yes, I know one could use TWO monitor receivers, but how many people have that?) 6. Mobile/portable transmit power is LOW, and the ~900 Mhz frequencies are extremely line-of-sight in their propagation, thereby limiting the receiving range of a casual eavesdropper to only a few miles under most circumstances. 7. There are no identifier transmissions made between cellular telephones and base stations which would enable the casual listener - even if he could decode them - to learn the actual identity of the calling telephone. 8. Cellular channel assignment for working communications is random. === Larry Lippman @ Recognition Research Corp., Clarence, New York === === UUCP {decvax,dual,rocksanne,rocksvax,watmath}!sunybcs!kitty!larry === === VOICE 716/741-9185 {rice,shell}!baylor!/ === === FAX 716/741-9635 {AT&T 3510D} ihnp4!/ === === === === "Have you hugged your cat today?" ===