- cypherpunks-legacy - lists.cpunks.org

Re: A possibility...
by gtoal＠an-teallach.com 17 Dec '03

17 Dec '03

:What I am thinking is to have one person encrypt using a RNG (noise). He :encrypts his message using the noise on one channel and then copies the noise :utilized on another channel. He then mixes the two channels to :create....noise. What you mean is generating a random one-time-pad, encrypting with that pad, and sending the pad to the recipient via secure means. I think it has been done before :-) If your idea of sending the 'random noise' is something electronic rather than a black bag, then all you've done is re-invent security through obscurity and your program is little more than hiding plaintext with a stego program. :On the other side the person must be expecting the noise and must know how to :seperate the signal. It seems that this leaves things open by having the :encryption key along with the message, but the message itself is just noise. :(i.e. the interloper must know of the signal, and know how to split it into :it's two components.) Oops. Sure sounds like you meant the security through obscurity option... :::::Comments? You design anything important for Microsoft then??? G

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A public alternative to clipper?
by an62213＠anon.penet.fi 17 Dec '03

17 Dec '03

> Also, the development of clipper was done with tax dollars. > The government has no need to recoup its investment in developing the > chip. Therefore, they can sell the chips at the cost of > manufacturing, and forget the R&D. That ability to ignore the bottom > line is a pretty powerful mechanism. If a clipper phone costs $100 > less than the alternative, because we the taxpayers already paid for > it, Clipper becomes more and more the only choice. Well, then. Maybe it's time to develop our own PGP chip. Would the PGP routines fit in a large PGA? What's the smallest, cheapest alternative we can come up with? If we give away the PGA code freely, that would help reduce the cost of inclusion in a commercial product. An FPGA would give the user the ability to change keys with little trouble. Upgrading is as easy as swapping a prom. (Better yet have an onboard programmer.) Even then, I would guess that a lot of people would have to pay a bit more for secure communications. I think it's worth it. ------------------------------------------------------------------------- To find out more about the anon service, send mail to help(a)anon.penet.fi. Due to the double-blind, any mail replies to this message will be anonymized, and an anonymous id will be allocated automatically. You have been warned. Please report any problems, inappropriate use etc. to admin(a)anon.penet.fi.

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PGP: change ".z" to ".gz" for gzip?
by nobody＠shell.portal.com 17 Dec '03

17 Dec '03

While browsing pgp.c, I noticed it checks for several kinds of compression: static char *compressSig[] = { "PK\03\04", "ZOO ", "GIF8", "\352\140", "HPAK", "\037\213", "\037\235", "\032\013", "\032HP%" /* lharc is special, must be last */ }; static char *compressName[] = { "PKZIP", "Zoo", "GIF", "Arj", "Hpack", "gzip", "compressed", "PAK", "Hyper", "LHarc" }; static char *compressExt[] = { ".zip", ".zoo", ".gif", ".arj", ".hpk", ".z", ".Z", ".pak", ".hyp", ".lzh" }; Since gzip now uses ".gz" consistently, perhaps the ".z" should change for PGP 2.5 (or whatever the next public version will be called). I think the code would have to change more to do the right thing with both, since it uses the compressSig to decide which compressExt to try -- is this right? I guess it'd be cleaner to accept both, but probably not worth extra code that would eventually become obsolete. Diogenes (Fingerprint 6FC5C2A5D1A0ED006B576AF7107D51FB)

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Promise her anything...
by mpd＠netcom.com 17 Dec '03

17 Dec '03

Hal writes: > Now, the more elaborate technology of digital cash can actually go a long > way towards solving this problem, at least in theory. With this approach, > each note has a unique serial number, and part of the agreement is that only > the first presentation of a note with any given serial number will be > honored. Then if the holder of a note wants to sell it to someone else, > they go through a protocol with the borrower in which he verifies that the > note has not been spent, and a new note is issued with a new serial number > that nobody has seen before. This way the buyer of the note is protected > against being sold an already-sold note. Plus, the digital cash technology > allows this to be done without the debtor finding out who is selling his > old notes to whom. There is no reason for him to have this information; the > holder of the note ought to be able to sell it privately, and this is > a good way of preserving that aspect of the transaction. Rather than have the holder and the person to whom the note is being sold go through a transaction with the issuer, one can have the issuer give his customers a cryptographically tamperproof software module which will prevent anonymous double-spending. This allows the digital cash system to work "offline" without having to connect to the bank every time two people wish to conduct a transaction. > Perhaps some form of registered mail for note redemptions, plus a requirement > that when a conflict like this arises both presenters must identify themselves, > could address some of these problems. (These problems arise for digital cash > just as much, by the way.) If you design the system so that cheating breaks the anonymity and identifies the perpetrator, then you can simply deter it in the same way we do with conventional instruments. Give the person a horrible credit rating and threaten to toss him in jail. -- Mike Duvos $ PGP 2.3a Public Key available $ mpd(a)netcom.com $ via Finger. $

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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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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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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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Re: Digital Cash
by jsday＠THUNDER.LakeheadU.CA 17 Dec '03

17 Dec '03

Mike Duvos <mpd(a)netcom.com> wrote: > Assuming the transactions are done via a tamperproof module > distributed by the issuer, and the math is arranged such that > using a note in multiple transactions reveals the perpetrator, > the system prevents anonymous double-spending while still > providing all the benefits of digital cash. How does the 'tamperproof' nature of the software help at all? It's still possible to double-spend in any off-line cash system by making multiple copies of the tamper-proof modules.. the only security provided is in obscuring the algorithm. Speaking of digital cash, many thanks to the author of the 'magic money' software. I am in the process of integrating it with a local bulletin board, which should hopefully be available on the net sometime this summer. :::*::: Jeremy S. Day.

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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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