December 2003 - cypherpunks-legacy

Dutch PGP ban
by Bradley W. Dolan 17 Dec '03

17 Dec '03

There are things about the impending PGP ban in the Netherlands which I can't understand. I lived in Wolfheze, The Netherlands, much of last year. The Dutch like to think of themselves as an open, tolerant society. In many ways, they are. Where they are not, they are usually subtle. This time, they are hardly being subtle. I don't know what that means. bdolan(a)well.sf.ca.us

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Re: Clipper (again)
by GRABOW_GEOFFREY＠tandem.com 17 Dec '03

17 Dec '03

dwomack(a)runner.jpl.utsa.edu writes: >4. What keeps someone in a high government office > from misusing these keys? Especially since > item 1 is illegal due to antiwiretap laws > anyway? Nothing!!! That's the whole point! I don't remember who said it first, although I think it was someone on this list, but key escrow is just like giving the gov't a copy of your house keys, just in case they get a court order to search your home. (This assumes you have a break-in proof house I don't know about the rest of you, but a gov't with my house key makes scares the $*&!!@ out of me! G.C.G. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | Geoffrey C. Grabow | "What we demand are rigidly defined | | Oyster Bay, New York | areas of doubt and uncertainty!" | | | -------------------- | | grabow_geoffrey(a)tandem.com | Clipper, SkipJack & Digital Telephony | | | JUST SAY NO!!! | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.3a mQCNAiz/qhsAAAEEAN4QxTfSBoeP/FCiaX0/KmCkl6BcKRa1PeoP6ZlPWydg1nOx yZAk8pIdgiGxxgiMBMsqD+SrU+Sl1Fx1AdJ14HJsBp1V6G4rBTZqvFpbNPCfrQfz K/Apg+7bBpi5Qv+sQ0TWIy38zp/laArgcdUOpE4oE2UOUBVEtYvm47K2P+i5AAUR tC9HZW9mZnJleSBDLiBHcmFib3cgPGdyYWJvd19nZW9mZnJleUB0YW5kZW0uY29t Pg== =2NWi -----END PGP PUBLIC KEY BLOCK-----

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WinPGP 1.0 is available!
by GRABOW_GEOFFREY＠tandem.com 17 Dec '03

17 Dec '03

My partner and I have just completed work on a Windows interface to D PGP 2.3a called WinPGP. This program gives you the easiest way to use PG from your Windows environment. It is available (or will be VERY soon) via anonymous FTP on ftp.eff.o Mech(a)eff.org will make an announcement with the details of its location. Cypherpunks write code! Enjoy, G.C.G. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | Geoffrey C. Grabow | "What we demand are rigidly defined | | Oyster Bay, New York | areas of doubt and uncertainty!" | | | -------------------- | | grabow_geoffrey(a)tandem.com | Clipper, SkipJack & Digital Telephony | | | JUST SAY NO!!! | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.3a mQCNAiz/qhsAAAEEAN4QxTfSBoeP/FCiaX0/KmCkl6BcKRa1PeoP6ZlPWydg1nOx yZAk8pIdgiGxxgiMBMsqD+SrU+Sl1Fx1AdJ14HJsBp1V6G4rBTZqvFpbNPCfrQfz K/Apg+7bBpi5Qv+sQ0TWIy38zp/laArgcdUOpE4oE2UOUBVEtYvm47K2P+i5AAUR tC9HZW9mZnJleSBDLiBHcmFib3cgPGdyYWJvd19nZW9mZnJleUB0YW5kZW0uY29t Pg== =2NWi -----END PGP PUBLIC KEY BLOCK-----

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Smile For Big Brother
by John K Clark 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I'm an engineer at a TV station, one of our microwave receivers at the 800 foot level of our broadcast tower has been getting an odd signal for almost 3 weeks, it's black and white video of a house and it's on 24 hours a day 7 days a week. Out of curiosity I decided to find the house, it wasn't too hard I knew the bearing and I knew exactly what the house looked like. It turns out the house is in a middle class neighborhood in Miramar Florida (about 30 miles north of Miami). The tiny camera and antenna are crudely mounted with duct tape on a telephone pole across the street , it looks like it taps into the power lines for electricity. Nobody would ever notice it unless you knew precisely where to look and what to look for. We are receiving the signal at 2458 megacycles but I think that's a second harmonic, the primary signal must be at 1229 meg, a government frequency, known to be used by the DEA. John K Clark johnkc(a)well.sf.ca.us -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLZJ3qnwRpTAWSvwVAQFsgwP8D+JmENH434G8QArys35R75dab5PA2ZHY PGLhH9u/hQh2kof3ZKjPtL1wfXlBvPRMwqBCJJWmkb9dDOvhxp4izc7eLMm/m8NK cYrii6gqz+E6c7V+A5ONhlqRxnw7mP0pOJ8wGI06lDneYb55SvnBIbssshYhFcTV kOb0tKG0MxY= =bvp/ -----END PGP SIGNATURE-----

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Re: Digital Cash
by Hal 17 Dec '03

17 Dec '03

I too would like to hear more about tamper-proof software modules. They would be a natural for software implementations of Clipper (although perhaps too slow for many applications). Imagine running the Clipper algorithm on your own computer and it comes out with your key exposed to listeners armed with the proper black box, yet you cannot disable this exposure. Interesting thought. I doubt that these would work as digital cash observers, though, even if possible. It seems to me that the digicash observer has to retain some internal state. In effect, it has to remember which coins you have spent and which you have not. You can cheat, then, by checkpointing your computer just before spending a coin. After you spend, you restore the computer to exactly the same state it was in before you spent it. You then go somewhere else and spend the coin again. The observer has no way of knowing that these games have been played with its state, yet you have obtained twice the value of the coin. Most of the observer-based protocols are also after-the-fact double- spending-detection protocols as well, so that if the observer is defeated you can still catch the miscreant eventually. But the two problems with this are, first, that it prevents the client from being anonymous to the bank, and second, that the cheater can still multiple-spend quickly and then escape the country before being caught. It was pointed out on sci.crypt some months ago the irony that Chaum's privacy-preserving cash relies on similar tamper-resistant technology to the privacy-destroying Clipper chip. Hal

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Insecurity of DES?
by Matthew J Ghio 17 Dec '03

17 Dec '03

There's been a lot of talk about how "easy" it is to break DES. As a mental exercise I decided to see just how difficult it would be for me if I really wanted to break a DES key. There are 116 publicly availiable unix workstations here on campus (DEC 3100s). Between 12 am and 8 am, there are rarely more than 50 users on the systems, including remote users. I could probably run processes on 50 of the unused machines for a few hours every night without being too much of a nuisance. Assuming I could try a million DES decryption operations a second on each (gross overestimation), how long would it take to brute force a DES key? Let's suppose for sake of argument that I could get the machines all day: 2^56 keys / 50 cpus / 1,000,000 per second / 60 seconds / 60 minutes / 24 hours = 16680 days = 45.7 years Of course, specially-designed hardware would be much faster.

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[comp.home.misc] Internet access/digicash
by Sameer 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- There has been a post to comp.home.misc about how we need net providers to keep accounts of where people access on the net so that they can be charged for the net services they use. I replied saying that we need it in a digital cash scheme. Those more knowledgeable about the specifics of digicash might want to check out that group and field any questions, if they may arise. -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLZMRqni7eNFdXppdAQHTrQQAkdRmUoq9OBO2dOW0sZO6w1TNPRi7FTF+ rLxvUdIjMBfFE8VI7ndBLZNbnBX/uuVvTrDyBjNLv1DGaoW/Bk+Ew9J5PDb383bE j3e4QslvTRDXhRatrC3diiqNLLi6Bm65JfTUic0izAqvLKpnNci3rzFdh0kw0x0n +Si5atV8ABA= =UifB -----END PGP SIGNATURE-----

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Run flat tires..
by Rob P. Martin 17 Dec '03

17 Dec '03

I was thinking about the way the FBI says it needs the telephony bill because with all the new technology they are loosing the ability to wiretap those people that are using these new comunication methods. Then I thought, hey wait a minute. What about all those poor police officers that are out chasing bad guys on the street. Right now, they have the ability, in a high speed chase, to stop the fleeing vehicle by placing a spike belt on the road. But now a new technology is arriving. Run flat tires! (You know those new fangled high tech tires, with a solid piece of rubber that allow you to run with no air pressure) Oh NO! What are these poor police officers to do? I think the government should help them out. I think that we need the Car Stopper bill. All new cars should be built with an electronic device that allows the police to shut off the engine remotely. This will help keep the status quo. And all those people they now use the spike belts against, will still be able to be caught. Let's just hope that the fequency that they choose doesn't get into the hands of car jackers, and other criminals.. Food for thought, they just might think of it next. *Shiver* Rob -- Rob P. Martin | "Too many people with too little to rpmartin(a)acs.ucalgary.ca | do, too much to say, and too --------------------------| and too little brains to handle This space for rent. | both at the same time." Apply within. | R.G. Wells

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:220 HELO T1A
by Istvan Oszaraz von Keszi 17 Dec '03

17 Dec '03

Hypothetical of hypothetical situations: - User has ISDN - User has PowerMac 8100-80 Needs a *secure* connection. Does any one know how I can chain it up? Is there a T1A connection to an Apple Nubus 90? Can I get a little bit of interference for a little privacy? Sorry to be the bother and thanks in advance. --

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Hypertext 'Hacker Crackdown'
by rishab＠dxm.ernet.in 17 Dec '03

17 Dec '03

Read Bruce Sterling's Hacker Crackdown through WWW! Hypertext indexed through a contents page... http://martigny.ai.mit.edu/~bal/sterling/contents.html ------------------------------------------------------------------------------- Rishab Aiyer Ghosh "What is civilisation rishab(a)doe.ernet.in, rishab(a)dxm.ernet.in but a ribonucleic Voicemail +91 11 3760335; Vox/Fax/Data 6853410 hangover?" H-34C Saket New Delhi 110017 INDIA -------------------------------------------------------------------------------

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Re: Run flat tires..
by Black Unicorn 17 Dec '03

17 Dec '03

-> I think the government should help them out. I think that we need the Car Stopper bill. All new cars should be built with an electronic device that allows the police to shut off the engine remotely. This will help keep the status quo. And all those people they now use the spike belts against, will still be able to be caught. <- LoJack was marketing such a device, I believe it's still available. The upshoot was: 1> Report your car stolen. 2> Police locate signal from LoJack 3> Signal sent to car telling it to kill ignition which it does. No chase, no mess. What stops police from killing the ignition of your car when they are interested in you, is an exercise for the reader.

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Real Digital Money
by mpd＠netcom.com 17 Dec '03

17 Dec '03

While we are discussing digital cash systems, I just happened to notice that a local BBS I use is now accepting a form of digital cash for subscriptions and services. They have solved the conversion problem between physical money and digital money in a rather interesting way which I thought I would pass along. Through a commercial firm by the name of True Media, Inc, located in Florida, one can obtain a 7 digit token in return for a $10 charge to ones phone bill by calling a 900 number. An automated voice system reads you the 7 digit number without the need for human intervention. Said tokens may then be enclosed in Email to the Sysop when requesting subscription upgrades and will be accepted as if they were real money. Although this is primitive compared to the protocols we have been discussing, it is kind of neat. Using an automated response system on a 900 number in order to convert dollars into digital tokens is an innovative approach. -- Mike Duvos $ PGP 2.3a Public Key available $ mpd(a)netcom.com $ via Finger. $

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Re:Insecurity of DES?
by VACCINIA＠UNCVX1.OIT.UNC.EDU 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Matthew Ghio wrote about a gedanken experiment in breaking DES: >45.7 years >Of course, specially-designed hardware would be much faster. See "Efficient DES Key Search" by Micheal J. Weiner, Bell-Northern Research, P.O. Box 3511 Station C, Ottawa, Ontario, K1Y4H7, Canada. Abstract. Despite recent improvements in analytic techniques for attacking the Data Encryption Standard (DES), exhaustive key search remains the most practical and efficient attack. Key search is becoming alarmingly practical. We show how to build an exhaustive DES key search machine for $1 million that can find a key in 3.5 hours on average. The design for such a machine is described in detail for the purpose of assessing the resistance of DES to an exhaustive attack. This design is based on mature technology to avoid making guesses about future capabilities. This manuscript is available by FTP but I don't remember where, does anyone else? At least for a known-plaintext attack, specially designed hardware of the type described in the paper is, indeed, much faster. The author mentions the prudence of using DES in triple-encryption mode. I like BIG keys. Scott G. Morham !The First, VACCINIA(a)uncvx1.oit.unc.edu! Second PGP Public Keys by Request ! and Third Levels ! of Information Storage and Retrieval !DNA, ! Biological Neural Nets, ! Cyberspace -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLZM1jj2paOMjHHAhAQGeZQP+NVjSVNT2vb5s414pMo3p+drsJYkDObri 7PLy2RNmwww1ZIUArBLwmivKGNoU6mZUBgk425rP7XzMMrYYrYxmrWM97XcC+fmv gwffcpKOSZ/OcjZ9n1EoD3jqSJR885ywqyY7Bqljx0Mj1YJ9NbJZ05FHrX/Int21 kc8XPiq8iPU= =90+w -----END PGP SIGNATURE-----

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Re: Real Digital Money
by mpd＠netcom.com 17 Dec '03

17 Dec '03

Kevin Q. Brown writes: > I'm intrigued about the use of a 900 number because I thought > that they were prohibitively expensive for a small-scale > business to run. I believe they cost a small fortune if you get the service from the phone company, with high startup and monthly minimum. There are, however, firms that act as resellers of the phone company service, and most of the smaller fly-by-night 900 operations do business with these. They can set you up as a 900 business inexpensively enough to allow even small enterprises to use 900 service. A lot of the weirder information hotlines come through such companies, and all you have to give them is a tape of your message and a small fee for the service -- Mike Duvos $ PGP 2.3a Public Key available $ mpd(a)netcom.com $ via Finger. $

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Re: Netherlands and Other European Countries
by Graham Toal 17 Dec '03

17 Dec '03

> P.S. Is anyone worried that the Netherlands seems on the verge of > banning PGP? Wasn't this country once a hacker's paradise? As for the Netherlands being a hacker's paradise....recall that telephone and other services are under the control of the "PTT" (Postal, Telegraph, and Telephone monopoly) that's so common in European countries. If they say "no modems may be attached," that's the law. (I don't know the current status, but at one time there were severe restrictions, heavy fees, etc.) .nl has that reputation because before last year phone phreaking specifically wasn't a criminal offense - if you could get free service off the telco by blowing whistles down their phones, that was the telco's loss. Last year they introduced new laws which made this illegal. The laws also appear to affect computer hacking, but the situation (last time I looked) was much less clear. Maybe someone has been charged by now so we'll know one way or another if the phone laws were successfully applied to computer hacking. Ask the guys at Hactic, De Zwarte Star, and BILWET (Amsterdam Association for the Dissemination of Illegal Science) about the surveillance done on them by the BVD, the Binnenlandse Veilegheids Dienst, the Dutch Internal Security Service. I'll save you the bother - this is from Hacktic from last year: Path: ibmpcug!ibmpcug!pipex!uunet!elroy.jpl.nasa.gov!lll-winken!telecom-request From: rop(a)hacktic.nl (Rop Gonggrijp) Newsgroups: comp.dcom.telecom Subject: Tapped Phone Message-ID: <telecom12.497.1(a)eecs.nwu.edu> Date: 19 Jun 92 07:09:19 GMT Sender: Telecom(a)eecs.nwu.edu Organization: Hack-Tic Magazine Lines: 187 Approved: Telecom(a)eecs.nwu.edu X-Submissions-To: telecom(a)eecs.nwu.edu X-Administrivia-To: telecom-request(a)eecs.nwu.edu X-Telecom-Digest: Volume 12, Issue 497, Message 1 of 7 I had a STRANGE experience with one of the Hack-Tic phones this week. It all started on Friday, June 12th when the modem hooked up to the Waffle station that is posting this message (and all the other traffic from and to the hacktic.nl domain) did not work anymore. I started up LanAssist to control the Waffle station and initiated a poll to our Internet host 'sun4nl'. The Waffle station is in our 'server closet'. It's an unattended and diskless 286 with no keyboard or monitor hooked up. The modem picked up the line and a high-pitched tone came from the modem speaker. So the modem is broken I thought. I started up Telix and 'talked' to the modem directly. Same high-pitched tone. I reset the modem. Same tone. This modem is fairly new, and although it had functioned properly most of the time, we were not really happy with it because the V42bis mode wasn't totally 'hang-proof'. So we concluded: the modem is broken. The next day Felipe and Paul came over and tried to fix the problem. Felipe and Paul are the Hack-Tic network trouble-shooting team. They brought two other high-speed modems to confirm that the modem was broken. They hooked up number one and tested it. Same high-pitched tone. After a few very puzzled looks we had to make a wild assumption: It wasn't our flaky equipment that was at fault; it could be the well-oiled machinery of The Phone Company that was messed up. Bill, our chief telephone engineer, well known to all of you for his 'sometimes-a-little-too-knowledgeble' posts quickly hooked up a telephone (that had not been attached to that line before) and picked it up. Same high-pitched tone. The dial-tone was audible in the background, but overpowered by the tone. The dialtone had been there all the time but the quality of the average modem speaker leaves something to be desired. When he hooked up our New York Telephone test-set he noticed that the high-pitched tone was even there when the phone was on the hook. Bill used the Demon-Dialer (our homebrew high-precision tone-generator) and found out that the tone was EXACTLY 3000 Hz, so it had to be crystal generated. This ruled out any spurious oscillations. As a last check we went to the point where all the wires come into our flat. We unscrewed the wires leading in and clipped the test-set onto the wires leading out. Same high-pitched tone. That Saturday night the error was reported to the PTT and that was it. So we thought. On Sunday the problem was still there (the PTT only fixes things in the weekend if you are a major customer that is planning on buying one of their PBXs). Bill checked to see that the tone was still there by picking up the test set that was still plugged in. Then I picked up our voice-line to make an outgoing call to Felipe. Bill's face went through several emotions within a few seconds. Finally he said 'Hmmm ... ehrr .... pfah ...'. When I looked at him rather puzzled he added: 'hgggggnaaaah ...'. I told Felipe to hold on. Bill started explaining that he heard my voice on the other line, but that it sounded scrambled. I asked Nils (who was also here, it's usually rather busy here) to talk to Felipe for a while and took the test-set from Bill. Yep, it was there all right. Scrambled voices. ------------------------------------------------------------- Short Intermezzo About Voice Scrambling One of the easiest ways to scramble someone's voice is to invert the speech. It works as follows: you take a tone and subtract the audio from it. In more technical terms: You single-sideband modulate the audio onto the tone. Dutch police uses this technique extensively for their medium security traffic. Every real scanner-freak has a retrofit in his scanner to undo this. It does keep the absolute lamers from listening in I guess. Speech inversion may be a quite simple process that does not involve many parts, but it is by no means something that happens at random. (Or at least not in a voice-frequency environment) ------------------------------------------------------------- Now there is a lot of thing that can go wrong in a phone system that cause a tone. Causing a frequency inversion of the audio on one line to another line is quite something else. Especially if you know that both lines are hooked up to different COs. The data line is hooked up to a fully digital Ericcson AXE switch, the voice line goes to a PRX (Processor Reed Exchange), which compares to a 1A/ESS in US terms. We spent the rest of that sunday looking for alternatives for what seemed to be the only possible conclusion: someone had hooked up something to our line that did not belong there. Even more so: they had messed up badly. I decided that the time had come for some social engineering. I had barely used my engineering skills since I had more or less given up on my active hack/phreak career and started publishing a hacker-magazine. This Monday (June 15th) I called the main access number of the PTT Amsterdam office and asked for the number of the Diemen 'hoofdverdeler', where my lines come in. The 'hoofdverdeler' is where all the lines for an entire area come in. They are split up to the offices serving that area from there. The phone at extension 2018 (+31 20 674 2018 to be precise) was answered by Fred. I explained that I was a service mechanic (I only used my first name, like they all do) at a customer's house and that there seemed to be a strange tone on the line. I was not the first to tell him of the problem. In fact, he had allready received a call from another service mechanic trying to fix the problem. He said that the line was rewired using colorcode-2, a code, he explained, that they don't normally use in that office. The in- and outgoing point for my data-line did connect according to his beep-device, but they were different wires. I asked him to follow the wires, and he did. He came back to the phone to tell me that my line had been hooked up to a small rack that he had never seen before. He looked further and concluded that it was the rack for internal lines to that building. When I asked him to clip my line loose from that rack he said that he could not do that. Because if it was not his color code, his instructions were not to mess with it. He said that this was the first time he saw so many of 'us from outside works' working on something. Knowing I could not convince him, and having all the information I wanted, I said goodbye and hung up. I thought about this for a while and decided to call Fred back and play it open with him. I told him that I was the subscriber, and not a technician. I told him what I thought the device was. He did not dispute my theory, but did not confirm it either. We chatted for quite a while. He wanted to know where my telephone knowledge came from, and I explained about Hack-Tic, phreaking, international signalling systems and so forth. When I asked him if he had seen lines with code-2 before he hasitated for about five seconds and said: 'Well, your line is being fixed. I'd say just wait and see'. I knew I was asking a question that he was not allowed to answer. We hung up. By this time our mailbox had been emptied, and it revealed a card from a service mechanic that had apparently tried to visit us early that moring (all morning is early to hackers). So I called the office and made an appointment for the morning of the next day, knowing that the problem would probably be gone by then. For the next few hours I heard people testing on the modem line (little ticks). But as evening came, the beep was still there. So early this morning, a man from the PTT arrived. He looked at the problem and was quite puzzled by it. He then said that they could not locate the problem, but that he believed that it was located between the office and me. In a sense this was true, because the 'hoofdverdeler' is indeed between the office and me. He decided to work around the problem. He whipped out a cell-phone and called his buddies at the other end. Together they put my line on a completely different wire leading from the CO to here. No more high-pitched tone. As I write this on Thursday afternoon, it all still needs a little time to sink in. It seems that the only conclusion is that somebody wanted to tap my lines, and hooked up the two lines that they wanted tapped to the in- and output of the tapping device instead of using two inputs. So the audio that was supposed to be fed to them (scrambled so that anybody just testing the wire could not hear what was going on) came back on my second line. The 3000 Hz tone was used to indicate that the line was not currently in use. As soon as I picked up, the tone would be replaced by a scrambled signal using the 3000 Hz as it's offset. So if this was a real attempt to tap us, they would have the two lines used to transport our audio hooked up to the in- and output of the second circuit. They would have tapped themselves. If you publish a hacker magazine, the notion that at least some of your phones are tapped some of time is not that far-fetched. Why do it so obvious? This could be an illegal tap. It could be one done by and for the PTT itself (they are the main subject of our publication after all). It could be ... Why guess. I'm not paranoid, and I don't want to be. If they tap my lines that is fine. Everything we say over the phone is considered public anyway. If they pay me, I'll transcribe all the important calls myself. Our network, used to spread information to and from the computer underground was down for two days. Now THAT PISSES ME OFF! Rop Gonggrijp (rop(a)hacktic.nl) from Amsterdam

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Re: Digital cash & multiple spending.
by GRABOW_GEOFFREY＠tandem.com 17 Dec '03

17 Dec '03

I work with many institutions that use or create POS systems. Some of them have gone to using tamper resistant smart cards that debit themselves and "can't be modified by a user.". The card has some keys and some crypto stuff in 'em that only allows authorized locations (those with the keys) to credit the balance on the card. It's my understanding that the cards cost around $7 and with care have a MTBF of 18-24 months. Additionally, these systems, which are offline, execute batch jobs at night to compare the spent monies with the balance in the bank's database. If anyone has gone over their limit, the card is flagged and a "HOT" card file is downloaded to the POS locations. The POS device will not allow "HOT" cards to be used. This limits multiple spending to a 24 hour period. G.C.G. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | Geoffrey C. Grabow | "What we demand are rigidly defined | | Oyster Bay, New York | areas of doubt and uncertainty!" | | | -------------------- | | grabow_geoffrey(a)tandem.com | Clipper, SkipJack & Digital Telephony | | | JUST SAY NO!!! | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.3a mQCNAiz/qhsAAAEEAN4QxTfSBoeP/FCiaX0/KmCkl6BcKRa1PeoP6ZlPWydg1nOx yZAk8pIdgiGxxgiMBMsqD+SrU+Sl1Fx1AdJ14HJsBp1V6G4rBTZqvFpbNPCfrQfz K/Apg+7bBpi5Qv+sQ0TWIy38zp/laArgcdUOpE4oE2UOUBVEtYvm47K2P+i5AAUR tC9HZW9mZnJleSBDLiBHcmFib3cgPGdyYWJvd19nZW9mZnJleUB0YW5kZW0uY29t Pg== =2NWi -----END PGP PUBLIC KEY BLOCK-----

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a citation sought..
by Herb Lin 17 Dec '03

17 Dec '03

I'm looking for the paper of last year that suggested how insecure 56 bit DES is against NSA-scale computers. Citation? Or if it's on line, so much the better. thanks.. herb

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EFF Pioneer award: I nominate Phil Zimmerman...
by gtoal＠an-teallach.com 17 Dec '03

17 Dec '03

Folks, with the political climate the way it is in the US at the moment, I think the EFF pioneer award has to make a political point as well as a technical one: I'll be nominating Phil Zimmerman. I hope others will too. Without Phil's pgp program, all our efforts against the Clipper chip would look very hollow indeed - he's given us a flag to rally round in the name of freedom. G

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(fwd) THE INTERNET CODE RING - PGP info
by tcmay＠netcom.com 17 Dec '03

17 Dec '03

Cypherpunks, I found this in alt.wired tonight. I don't recall seeing this particular interview published before, but I could be losing track of what's out there---Zimmermann has been interviewed a lot. We (Cypherpunks) are mentioned in the interview. --Tim May From: jsquires(a)nic.cerf.net (James A. Squires) Newsgroups: alt.wired Subject: THE INTERNET CODE RING - PGP info Date: 23 Mar 1994 06:58:47 GMT Organization: CERFnet Lines: 370 Keywords: PGP This was sent to me. I found it a great explanation for how PGP works (non-tech), and the concept of a public key. It is an interview with the author. Hope y'all find in useful ^_^ -JAS -------------------------------------------------------------- THE INTERNET CODE RING! An Interview with Phil Zimmerman, creator of PGP We were sitting in a circle on the floor at the Computers, Freedom, and Privacy conference, March '93 in San Francisco, St. Jude and I with Tom Jennings, Fen La Balme, et al, discussing encryption and other neophiliac rants when a dapper fellow wandered by with a beard on his face and a tie hanging from his neck. He picked up Jude's copy of bOING-bOING number 10 and glanced through it, clearly interested. I later learned that this was Phil Zimmerman, creator of PGP ("Pretty Good Privacy"), so I tracked him down and we talked for the record. Jon: I'm fairly nontechnical, and I'm also new to encryption. I spent some time recently on the cypherpunks' list, and I have a pretty good sense of what's going on, but maybe you can tell me in your own words how you came to write PGP, and what your philosophy is, especially with distribution. Phil: Well, okay. PGP, which means "Pretty Good Privacy" is a public key encryption program, it uses a public key encryption algorithm, which means that you can encrypt messages and you can send them to people that you've never met, that you've never had a chance to exchange keys with over a secure channel. With regular encryption, the kind that everybody has heard about, you encrypt a message, it scrambles it up, renders it unintelligible, and then you send it to someone else, and they can descramble it, decrypting it. They have to use the same key to decrypt it as you used to encrypt it. Well, this is a problem, this is inconvenient, because how are you going to tell them what that key is, what're you going to do, tell them over the telephone? If someone can intercept the message, they can intercept the key. So this has been the central problem in cryptography for the past couple of millenia. There's been a lots of different ways of encrypting information, but they all have this problem. If you had a secure channel for exchanging keys, why do you need any cryptography at all? So, in the late 1970s, somebody came up with an idea for encrypting information with two keys. The two keys are mathematically related. You use one of the keys to encrypt the message, and use the other key to decrpyt the message. As a matter of fact, the keys have a kind of yin-yang relationship, so that either one of them can decrypt what the other one can encrypt. So everybody randomly generates a pair of these keys, the keys are mathematically related, and they can be split apart like cracking a coin in half, and the jagged edges stick together just right. They can publish one of the keys, and keep the other one secret. Now, unlike cracking the coin in half, you can't look at the jagged edge, and figure out what the other jagged edge is going to look like. In fact, you can't look at the published key and figure out what the secret key is without spending centuries of supercomputer time to do it. This means that any time anybody wants to send you a message, they can encrypt that message with your public key, and then you can decrypt the message with your secret key. If you want to send them a message, then you can encrypt the message with their public key, and then they can decrypt it with their secret key. Everybody who wants to participate in this system can generate a pair of these keys, publish one of them, and keep the other one secret. Everybody's published key can end up in a big public key directory, like a phone book, or an electronic bulletin board, or something like that. You can look up somebody's public key, encrypt a message to them, and send it to them. They're the only ones that can read it, because they're the only ones that have the corresponding secret key. J: Are there any such directories now? P: Well, actually, there are starting to be directories like that. For PGP, there are some public key directories on Internet. You can just send an electronic inquiry saying "Give me the key for [somebody]," and it'll send you their key back, their public key. J: The convention I've seen has been the inclusion of the public key in an email message posted to a mailing list. P: You can do that, you can include your own public key when you send a message to someone, so that when they send you a reply, they'll know what public key to use to send the reply. But the problem...there is an achilles heel with public key cryptography, and I'll get to that in a minute. But first, let me explain authentication. If I want to send you a message, and prove that it came from me, I can do that by encrypting it with my own secret key, and then I can send you the message, and you can decrypt it with my public key. Remember I said that the keys are in this yin-yang relationship, so that either one can decrypt what the other one encrypts. If I don't care about secrecy, if I only cared about authentication, if I only wanted to prove to you that the message came from me, I could encrypt the message with my own secret key and send it to you, and you could decrypt it with your public key. Well, anyone else could decrypt it to, because everyone has my public key. If I want to combine the features of secrecy and authentication, I can do both steps: I can encrypt the message first with my own secret key, thereby creating a signature, and then encrypt it again with your public key. I then send you the message. You reverse those steps: first you decrypt it with your own secret key, and then you decrypt that with my public key. That's a message that only you can read and only I could have sent. We have secrecy and authentication. So you get authentication by using your own secret key to decrypt a message, thereby signing the message. You can also convince third parties like a judge that the message came from me. That means that I could send you a financial instrument, a legal contract or some kind of binding agreement. The judge will believe that the message did come from me, because I am the only person with the secret key, that could have created that message. Now, public key cryptography has an achilles heel, and that achilles heel is that, suppose you want to send a message to someone, and you look up their public key, on a bulletin board, for example. You take their public key and you encrypt the message and then send it to them, and presumably only they can read it. Well, what if Ollie North broke into that BBS system? And he subsituted his own public key for the public key of your friend. And left your friend's name on it, so that it would look like it belonged to your friend. But it really wasn't your friend's public key, it was Ollie's public key that he had created just for this purpose. You send a message, you get the bulletin board to tell you your friend's public key, but it isn't your friend's public key, it's Ollie's public key. You encrypt a message with that. You send it, possibly through the same bulletin board, to your friend. Ollie intercepts it, and he can read it because he knows the secret key that goes with it. If you were particularly clever, which Ollie North isn't because we all know that he forgot to get those White House backup tapes deleted...but suppose he were clever, he would then re-encrypt the decrypted message, using the stolen key of your friend, and send it to your friend so that he wouldn't suspect that anything was amiss. This is the achilles' heel of public key cryptography, and all public key encryption packages that are worth anything invest a tremendous amount of effort in solving this one problem. Probably half the lines of code in the program are dedicated to solving this one problem. PGP solves this problem by allowing third parties, mutually trusted friends, to sign keys. That proves that they came from who they said they came from. Suppose you wanted to send me a message, and you didn't know my public key, but you know George's public key over here, because George have you his public key on a floppy disk. I publish my public key on a bulletin board, but before I do, I have George sign it, just like he signs any other message. I have him sign my public key, and I put that on a bulletin board. If you download my key, and it has George's signature on it, that constitutes a promise by George that that key really belongs to me. He says that my name and my key got together. He signs the whole shootin' match. If you get that, you can check his signature, because you have his public key to check. If you trust him not to lie, you can believe that really is my public key, and if Ollie North breaks into the bulletin board, he can't make it look like his key is my key, because he doesn't know how to forge a signature from George. This is how public key encryption solves the problem, and in particular, PGP solves it by allowing you to designate anyone as a trusted introducer. In this case, this third party is a trusted introducer, you trust him to introduce my key to you. There are public key encryption packages currently being promoted by the U.S. Government based on a standard called Privacy Enhanced Mail, or PEM. PEM's architecture has a central certification authority that signs everybody's public key. If everyone trusts the central authority to sign everyone's key, and not to lie, then everyone can trust that they key they have is a good key. The key actually belongs to the name that's attached to it. But a lot of people, especially people who are libertarian-minded, would not feel comfortable with an approach that requires them to trust a central authority. PGP allows grassroots distributed trust, where you get to choose who you trust. It more closely follows the social structures that people are used to. You tend to believe your friends. J: Did you make a conscious decision up front, before you started programming PGP, that you were going to create something that would be distributed in this grassroots way, free through the Internet. P: Well, there were some software parts of PGP that I developed some years ago, as far back as 1986, that I developed with the intention of developing commercial products with it someday. Over the years that followed, I developed a few more pieces that I hoped someday to turn into a commercial product. But, when it finally came down to it, I realized that it would be more politically effective to distribute PGP this way. Besides that, there is a patent on the RSA public key encryption algorithm that PGP is based on. I wrote all of the software from scratch. I didn't steal any software from the RSA patent holders. But patent law is different from copyright law. While I didn't steal any software from them, I did use the algorithm, the mathematical formulas that were published in academic journals, describing how to do public key cryptography. I turned those mathematical formulas into lines of computer code, and developed it independently. J: Did you originally intend to license that? P: When I first wrote the parts of it back in 1986, I did. But I began in earnest on PGP in December of 1990. At that time, I had decided that I was going to go ahead and publish it for free. I thought that it was politically a useful thing to do, considering the war on drugs and the government's attitude toward privacy. Shortly after I stared on the development, I learned of Senate Bill 266, which was the Omnibus Anticrime Bill. It had a provision tucked away in it, a sense of Congress provision, that would, if it had become real hard law, have required manufacturers of secure communications gear, and presumably cryptographic software, to put back doors in their products to allow the government to obtain the plain text contents of the traffic. I felt that it would be a good idea to try to get PGP out before this became law. As it turned out, it never did pass. It was defeated after a lot of protest from civil liberties groups and industry groups. J: But if they could get away with passing it, they would still take the initiative and try. P: Well, yeah, actually...it started out as a sense of Congress bill, which means that it wasn't binding law. But those things are usually set to deploy the political groundwork to make it possible later to make it into hard law. Within a week or so after publishing PGP, Senate Bill 266 went down in defeat, at least that provision was taken out, and that was entirely due to the efforts of others, I had nothing to do with that. PGP didn't have any impact, it turned out, at all. So that's why I published PGP. J: Several of my friends are involved in cypherpunks, and I've been on their mailing list...are you affiliated in any way with cypherpunks? Are you getting their mailing list? P: I was on their mailing list for a couple of days, but I found that the density of traffic was high enough that I couldn't get any work done, so I had them take me off the list. J: The reason I bring cypherpunks up is that they seem to have almost a religious fervor about encryption <laughs>. I was wondering if you share that. P: I don't think of my own interest in cryptography as a religious fervor. I did miss some mortgage payments while I was working on PGP. In fact, I missed five mortgage payments during the development of PGP, so I came pretty close to losing my house. So I must have enough fervor to stay with the project long enough to miss five mortgage payments <laughter>. But I don't think it's a religious fervor. J: I'm impressed with the way encryption in general and PGP in particular have caught on with the press, how it's become within the last year. P: Well, PGP 1.0 was released in June of '91. It only ran on MS DOS, and it didn't have a lot of the features necessary to do really good key certification, which is that achilles' heel that I told you about. Theoretically, you could use it in a manual mode to do that, but it wasn't automatic like it is in PGP 2.0 and above. The current release of PGP is 2.2. It's a lot smoother and more polished that 2.0 was. 2.0 was tremendously different than 1.0, and the reason the popularity has taken off so much since September, when it was released, is because it ran on a lot of UNIX platforms, beginning with 2.0. Since the main vehicle for Internet nodes is UNIX platforms, that made it more popular in the UNIX/Internet world. Since Internet seems to be the fertile soil of discourse on cryptography, the fact that PGP 2.0 began running on UNIX platforms has a lot to do with it's popularity since that version was released...Tthat was in September of '92. J: The easiest way to get PGP is through FTP from various sites? P: Yeah. Most of them European sites. PGP 2.0 and above was released in Europe. The people that were working on it were out of reach of U.S. patent law...and not only are they out of reach of patent law, but it also defuses the export control issues, because we're importing it into the U.S., instead of exporting it. Also PGP 1.0 was exported, presumably by somebody, any one of thousands of people could have done it...but it was published in the public domain. It's hard to see how something like that could be published, and thousands of people could have it, and it could not leak overseas. It's like saying that the New York Times shouldn't be exported, how can you prevent that when a million people have a copy? It's blowing in the wind, you can't embargo the wind. J: And by beginning in Europe, you sort of fanned the flame that much better. P: Yeah. J: It seems to have spread globally, and I'm sure that you're hearing a lot about it, getting a lot of response. P: Particularly at this conference (CFP93), yes. J: Do you plan to do more development of PGP, or are you satisfied with where it is.... P: PGP will be developed further. My personal involvement is more in providing design direction and making sure that the architecture stays sound. The actual coding is taking place overseas, or at least most of it is. We do get patches sent in by people in the U.S. who find bugs, and who say, "I found this bug, here's a patch to fix it." But the bulk of the work is taking place outside the U.S. borders. J: Is there a Mac version as well as a DOS version now? P: Yeah, there is a Mac version...there was a Mac version released shortly after PGP 2.0 came out. Somebody did that independently, and I only found out about it after it was released. People have written me about it, and it did seem to have some problems. The same guy who did that version is doing a much improved version, Mac PGP version 2.2, which I believe should be out in a few days...that was the last I heard before I came to the conference. The second Mac development group, that's working on a very "Mac"-ish GUI, is being managed by a guy named Blair Weiss. That takes longer, it's difficult to write a good Mac application, so it's probably going to be a couple of months before that hits the streets. J: Were you involved in the UNIX version, too? P: I did the first MS-DOS version entirely by myself, but it's not that big a distance between MS-DOS and UNIX, so most of it was the same. The UNIX board took place soon after PGP 1.0 was released. After that, many other enhancements were added, and major architectural changes took place to the code, and that's what finally made its way out as version 2.0. J: You're doing consulting now? P: That's how I make my living, by consulting. I don't make anything from PGP. J: Do you think you'll just let PGP take a life of its own, let other people work on it from here out? P: Other people are contributing their code, and other people are adding enhancements, with my design direction. Perhaps someday I'll find a way to make money from PGP, but if I do, it will be done in such a way that there will always be a free version of PGP available. J: I was thinking of the UNIX thing, where everybody's modified their versions of the UNIX Operating System so that some [customized versions] weren't even interoperable. I was wondering if there was a chance that PGP would mutate, whether you're going to keep some sort of control over it, or whether people will start doing their onw versions of it.... P: Well, I don't know, that could happen. There are so many people interested in the product now, it's hard to keep track of everybody's changes. When they send in suggested changes, we have to look at it carefully to see that the changes are good changes. J: But you don't have some sort of structure in place where you do some kind of approval if somebody wants to make some kind of mutant version of PGP.... P: There is a kind of de facto influence that I have over the product, because it's still my product, in a kind of psychological sense. In the user population, they associate my name with the product in such a way that, if I say that this product is good, that I have looked at this and that I believe the changes made sense the last version are good changes, that people will believe that. So I can determine the direction, not by some iron law, not by having people work for me that I can hire and fire, but more by my opinion guiding the product. It would not be easy for a person to make a different version of PGP that went in a different direction than how I wanted it to go, because everybody still uses the version that I approved, so to be compatible...this has a kind of intertia to it, a de facto standard. PGP currently, I believe, is the world's most popular public key encryption program, so that has potential to become a de facto standard. I don't know what that means in comparison to the PEM standard. PEM is for a different environment than PGP, perhaps, although the PGP method of certifying keys can be collapsed into a special case that mimics in many respects the PEM model for certifying keys. --- [ End Of Line ] ---

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Status of crypto cash bank in Texas?
by James G. Speth 17 Dec '03

17 Dec '03

Could someone fill me in on the current status of the crypto-credit union that is being started in Austin? I hear sporadic mention of it, but I haven't seen an update lately. How can I contact those who are working on it? Eagerly awaiting the decline of paper, Jim ________________________________________________________________________________ james speth email for pgp compatible public-key december(a)end.com ________________________________________________________________________________ Have you ever had your phones tapped by the government? YOU WILL and the company that'll bring it to you... AT&T

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DIGICASH:Re: observer chips
by wcs＠anchor.ho.att.com 17 Dec '03

17 Dec '03

> I have always been skeptical of this observer-chip approach, because it > wasn't clear that it was feasible to make a tamper-resistant chip > economically, and because the specialized hardware that would be > required would prevent the system from being used on widely-available PCs. Well, the government pretends they can do a tamper-proof chip, complete with wiretap keys installed by the wizards behind the curtain, for $36. That's $26 for the chip in qty 10,000, plus a subsidized $10 for tapping service and key installation. I thought Mykotronx's press releases had sounded more like they wanted $36 themselves, and I don't know the price for VLSI Inc's tamper-proof technology, but it may not be far off. As far as interfaces go, PCMCIA are nice, but there's not much data to transfer in most digicash exchanges, so a dumb cheap serial interface may be more realistic, since everything supports it. Bill Stewart

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Re: Digital Cash
by John.Schofield＠f903.n102.z1.fidonet.org 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- <Quoting UUCP to John Schofield about "Re: Digital Cash"> Uu> Speaking of digital cash, many thanks to the author of the Uu> 'magic money' software. I am in the process of integrating it Uu> with a local bulletin board, which should hopefully be available Uu> on the net sometime this summer. Does anyone have any more information about this? Sounds interesting, if I knew what it was. John Schofield ... "But other than that, Mrs. Lincoln, how did you like the play?" -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLZMOzGj9fvT+ukJdAQFmUQP7B83Qi94KDAvQIJu4roshEW6jCpHbof27 jogypWUA8/qMjA2B5AgzS6gtRXmka3fW3SC4MKcMLULX88wqu0/LJFiCZCVxp9md jVxIx4VuJyGD4fy6d8kF9YlXv/aJ/RjMktiYji+7NnR9Q0JcbbjDR7FJZXixJGT7 5KL7d4m4YO0= =K1IG -----END PGP SIGNATURE----- --- Blue Wave/RA v2.12 -- : John Schofield - via mcws.fidonet.org - Public Access (213)256-8371 : ARPA/INTERNET: John.Schofield(a)f903.n102.z1.fidonet.org : UUCP: ...!cheshire!mcws!903!John.Schofield : Compu$erve: >internet:John.Schofield@f903.n102.z1.fidonet.org

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Re: a citation sought..
by smb＠research.att.com 17 Dec '03

17 Dec '03

I'm looking for the paper of last year that suggested how insecure 56 bit DES is against NSA-scale computers. Citation? Or if it's on line, so much the better. More precisely, it's special-purpose hardware, not NSA-scale computers. See ftp.eff.org:/pub/EFF/Policy/Crypto/Misc/Technical/des_break.ps.gz. There are other papers in that directory that you may find of interest.

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Please refer back to the original purpose of the message
by jdwilson＠gold.chem.hawaii.edu 17 Dec '03

17 Dec '03

Mr. May et al: The couple of lines re pornographic language seems to have diverted the apprecation of the problem reported in the message. This message is about whether or not Compu$erve should get away scott free for bullying one of their subscribers while they attempt to steal use of his trade- marked software which he had been offering on Compu$erve for some time. Please reread the msg. > Forwarded from a message on InterNet: > Forwarded message: > > X-Mailer: ELM [version 2.3 PL8] > > To supporters of freedom of speech - please read, act and > > share this as your conscience dictates: > > Unofficially excerpted from Infoworld 3/7/94 Brian Livingston's > > Window Manager column. > > > > "Can CompuServe succeed in silencing Windows dissenters? Having > > your electronic mail account cut off is the modern equivalent > > of solitary confinement. Many services I use, such as Microsoft > > Windows forums, exist exclusively on systems such as the CompuServe > > Information Service. There is no other place for information. > > "That's why I took notice when CompuServe threatened to cut off > > a subscriber's account if he even mentioned on-line a lawsuit that > > the company filed against him. > > > > "Compuserve filed suit January 31 in Federal District Court in Ohio > > against Richard S. Patterson, the developer of a shareware program > > called Windows Navigator (WinNAV), which he has distributed on > > Compuserve for several years. > > > > This suit came about after Patterson complained on a Compuserve > > forum last December that the company's plans to release a product > > called Windows Navigator infringed upon his trademarks. > > "Prior to initiating the suit, Compuserve modified the name of its > > product to CompuServe Navigator, Windows Version. It asks the court > > to find that Patterson has "no trademark rights" that it has > > infringed, and for an unspecified monetary penalty. > > > > "I don't know who will prevail in this suit. But what really > > bothers me is this threat in a letter to Patterson dated January 31, > > from Kevin J. Osterkamp, Compuserve's attorney in the firm of > > Roetzel and Andress, of Columbus, Ohio; > > > > "I am as legal counsel for Compuserve compelled to advise you that > > it is Compuserves position that you will be terminated if you > > mention, discuss, or comment upon the lawsuit or the issues > > related thereto as a part of the CompuServe Information Service. > > Termination will also result from any other disparagment of > > Compuserve, its management, employees, or business practices. > > > > "I've never met Mr. Patterson, but I know him tangentially from > > his other software, Zip Tools, which appears in Windows Gizmos. > > > > "My columns have promoted CompuServe many times, so I asked for > > it's position. The gist of the reply I received from Mr. Oster- > > kamp was this: > > > > "Regarding the case of Compuserve vs. Patterson, my ethical > > obligations (and Mr. Patterson's) prohibit me from commenting > > directly on the case. I can, however, assure you that our > > request that Mr. Patterson stop using Compuserve's online > > services to disparage the company is simply good, old-fashioned > > common sense. After all, why should CompuServe - or any online > > service - allow a disgruntled party the opportunity to bad- > > mouth the company in its own forum? > > > > "Why, indeed? It's called "a free exchange of ideas." It is > > much sought after by people around the world. > > > > "If AT&T could cut off my phone because I criticized them while > > using long distance, we would be in very serious danger of losing > > our freedom. > > > > "It is unclear whether electronic services are "common carriers" > > (like AT&T) that must carry all communications, or "publishers" > > (like magazines) that are legally responsible for the words they > > choose to print. > > > > "But Compuserve knows which it prefers to be. In separate cases, > > it has been sued by the National Music Publishers Association and > > Cubby Inc. for distributing material uploaded by subscribers. > > > > Compuserve argues that it should be free from any liability > > because "it is a distributor and not a publisher." > > > > "Our future "information highway" will inevitably center on just > > five or six giant corporations. That's why it's so important > > that access not be denied to someone whom these entities don't > > like. > > > > "Do me a favor. Sit down right now and tap out a message to > > Mauryve Cox, the CEO of Compuserve. His I.D. number is > > 70003,1550. Tell him how important it is to you that no one > > be denied access to Compuserve forums. Send me a copy, > > if my account still works after this column appears. > > > > (Brian Livingston is the author of "Windows 3.1 Secrets" and > > "More Windows Secrets", and co-author of "Windows Gizmos." > > Send tips to Compuserve: 70053,2035; or fax: (206) 282-1248.)

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Re: Digital Cash
by smb＠research.att.com 17 Dec '03

17 Dec '03

Just a thought on ways to deter all of this multiple spending gunk - when you start off, have a centralized bank server. While traffic is low, you can have each individual certificate cleared with the bank server upon creation and execution. As someone else noted, ``crypto is all economics''. In the New York City subway system, the new fare card readers are all linked to a central computer, specifically to prevent double spending. They could have used smart cards and fancy crypto -- but this is cheaper, especially because they have an excellent handle on the maximum load -- the number of subway riders at rush hour. Fancy technology could get them into an ``arms race'' with rip-off artists, who reverse-engineer cards, crack algorithms, etc. Digital cash -- which provide anonymity, as contrasted against cryptographically-signed debit card transactions -- will become a reality if and only if someone finds it more profitable than the alternative, after deducting the costs for observer chips, licenses for Chaum's patents, etc. Some people are willing to pay for privacy -- but are there enough of them to make it pay? --Steve Bellovin

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