- cypherpunks-legacy@lists.ogf.org

Suggest splitting things up
by Eric Hughes 04 Dec '92

04 Dec '92

A word on the subject of altering the list from the list maintainer. There's been lots of discussion about splitting up the list into various pieces. In a word, it's not going to happen. Look, this is the cypherpunks list. Cypherpunks write code. A corollary to this is that cypherpunks take responsibility for the volume of mail they receive. If you're getting too much mail, use a filter. Many of you may not know that the remailer software as currently configured pressed into service just such a filter. In the just-announced ftp site, there's the source code, in perl, to just such a filter. You can change it to do whatever you like. In particular, you can install it to filter all your cypherpunks mail to a separate mailbox, file, or subdirectory. You can also use MH, whose slocal the above perl filter was based on. slocal can filter all of your cypherpunks mail to separate places. You can also send all of your cypherpunks mail to a separate directory and use a newsreader to read it. I've never done this, but certain list members have. If one of them (say, Mitra, who recently mentioned that he does this) would post a short summary of how it's done to the list and offer to answer questions off-line, I'd appreciate it. Eric

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Re: digital banking
by ghsvax!hal＠uunet.UU.NET 04 Dec '92

04 Dec '92

I enjoyed seeing Karl's walk-through of Chaum's digital cash algorithm. The numbers looked right. One point is that doing different denominations isn't that much harder, you just need to have more exponents. As you generate your primes p and q, make sure that p-1 and q-1 aren't divisible by any small primes (other than 2). This will ensure that phi = (p-1)(q-1) is not divisible by small primes, hence that gcd(e, phi) will be 1 for those same small primes, in fact for all the odd numbers. Karl also quoted a comment from Ray Cromwell expressing concern over proving deposits. Ideally you'd get a signed receipt from the bank for every deposit you make. In the case of electronic deposits, there exist protocols for "gradual secret exchange" that might be suitable for this purpose. What you'd like is to send the bank your deposit "gradually", while the bank simultaneously gradually sends you a digitally signed receipt. I don't recall the details of these protocols. Gradual exchange would not be very convenient for email because of the long turnaround times in mail systems, but if you had a better connection it might be useful, especially for large deposits. Another way to look at it is, what stops the local merchant from taking your payment, putting it in his pocket, and then denying that you've given him anything? It would just be his word against yours. One answer is, if he does that to multiple people, their multiple stories would have more credibility than his denials. Similarly, a bank which made a habit of cheating its customers would find itself publically exposed. So it may be reasonable to trust the bank for routine transactions. Hal 74076.1041(a)compuserve.com

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Brand-spanking new key
by cordones＠IMAGE.CS.NYU.EDU 04 Dec '92

04 Dec '92

Hello everyone. I just finished installing PGP2.0 in a rush...so..here goes my 1024-bit Military grade (he..guess I am a little paranoid..) key. Give it a try and perhaps I will experience some ESP... -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.0 mQCNAisdxzYAAAEEALaDepo7QeCT2MCu+02nGuAZIJtoRwbxlwulUT/SehKH7xFW 43UqHZKHwMjDT5S8TESpGLtanhKsgmGa+Pp1X/tEImS2CqEvnPQhy0mjQMqR1WZ7 NfKenvUesXkE6pTpg/8Fk1AwsqRiypUEHoiNeU4k14gceilSg2Z/lrxl5FyxAAUR tCNFbCBab3JybyA8Y29yZG9uZXNAcm9ib2NvcC5ueXUuZWR1Pg== =o+Oh -----END PGP PUBLIC KEY BLOCK----- so..have phun... El Zorro

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Re: Suggest splitting things up
by DrZaphod 04 Dec '92

04 Dec '92

In Message Wed, 2 Dec 92 21:56:54 PST, Eli Brandt <jarthur.Claremont.EDU!ebrandt(a)netcomsv.netcom.com> writes: > I personally don't object to this kind of list volume. Neither do I, just to cast my vote in the hat. In fact, I don't even think that we need to tag the messages for the type of content. I'm interested in anything that is posted in this list and read every message. TTFN! DrZaphod [AC/DC] / [DnA][HP] [drzaphod(a)ncselxsi.uucp] Technicolorized

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Re: Secure key exchange
by edgar＠spectrx.Saigon.COM 03 Dec '92

03 Dec '92

Anserwing some comments about my suggestions for key verification. Phil Karn pointed out that the next version of PGP will display an MD-5 hash of any public key for phone comparison purposes. That's great, but that version of PGP isn't here quite yet. I suspect, in any case, that the added security isn't all that great since I suspect it's very hard to find another valid key-pair where the public key matches the last 24 bits plus some fragment of another 20 bits or so from the middle of the key. Phone, as opposed to mailed paper verifications has the following problems: Phil says you have to recognize the voice, which implies you've met him in close quarters, which implies you could have exchanged keys physically anyway. If the only place you've heard the voice is over the phone, that's not a very good criterion. Phone verification is good, IMHO, *only* if the person being verified is *called at a listed number*. You can't verify a person who calls you, (unless you know the voice). You can't verify a person you call at an unlisted number which you got over the net!! Economics: Net participants are scattered over the country and even the world. Paper verification costs about $2-$3 allowing for my fee, copying costs and two-way international postage. Adding notarization adds about $5.00. Phone verification is economical locally (maybe cheaper than mail), but more expensive when long-distance rates apply, especially international rates. Meeting at parties or face-to-face is most expensive of all, unless the meeting happens fortuitously. Overseas plane fare to exchange keys is beyond the means of most of us. Phil says: I would much rather trust a simple verification procedure based on redundancy and close personal relationships than a single, complex, impersonal process involving people I don't know. This is not to impugn your integrity, of course -- I'm simply speaking on principle. No offense taken! I, on the other hand, would rather have in my hand a signed statement of identity with photocopied ID that I can keep and file away. I also don't want to go broke making international phone calls. As it happens, I, so far, have not been able to sign a single key!! I called Phil Zimmerman at a listed number, I read him my key and he signed it, but he was called away from the phone before he could verify his key to me. So I can't sign his! I've met a few people at parties I've given my paper key (fragments) to. So far none of them have signed my key, but none of them had paper key fragments to trade, so I can't sign theirs. George Gleason commented about supplying home addresses. Your comments are well taken. Phil Zimmerman also commented to me in E-mail that some people don't want the serial numbers on their photo ID copied. Everyone please feel free not to supply a home address and to obscure any home address or serial number on the photocopied photo ID. I'll still sign your key, although I'll note what you did in my signed key directory, which I'll send to customers & publish here. If you don't want *me* to know your home address, you can use a P.O. box for me to return my (or other customers') ID certificate(s) to you. On the other hand, as the service provider, MY home address and phone are public info. I also acknowledge George's criticism re the "I'm not a cop" statement. I'm going to leave it in my statement, because it's true, but in general you should be aware that any legal protection is questionable at best. The lack of protection has been verified by a source on Extropians and by an attorney on the RIME network. In the meantime, I guess we can discuss illegal subjects not with "I've done ..." but with "I've heard that ..." or "I used to know somebody who ...". Also anonymous remailers will be a big help. -- edgar(a)spectrx.saigon.com (Edgar W. Swank) SPECTROX SYSTEMS +1.408.252.1005 Silicon Valley, Ca

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Re: digest (not splitting)
by andrew_derry＠sfu.ca 03 Dec '92

03 Dec '92

Richard Childers <rchilder(a)us.oracle.com> says: >So do I, but a digest ( 225 / 4 == 56.25 messages per day, concatenated >into one giant digest of messages, sans headers ) would also make the >traffic manageable, while preserving the ability for the various groups >to benefit from one another's divergent, but relevant, insights into the >overall process and its possible applications. I'm for the digest format. Should make it much more managable. --- Andrew Derry | ACS@HCC - Simon Fraser University | Internet: derry(a)sfu.ca |

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RE: digital banking, file formats, etc.
by DrZaphod 03 Dec '92

03 Dec '92

In Message Wed, 2 Dec 92 20:17:19 -0600, Karl L. Barrus <tree.egr.uh.edu!barrus(a)netcomsv.netcom.com> writes: >1) Alice chooses x, r > Alice computes B = r^3 * f(x) mod n > Alice sends the following message to the bank via an anonymous >remailer > > :: > withdraw > <account name> > <B = r^3 * f(x) mod n> > Reply-To: <an anonymous remailer> > <remailing request to Alice encrypted with appropriate remailer >public key> > What happens if the bank mails $$$ to Alice. Somebody intprive Alice of HER money. I havn't read much about digital money protocols so correct me if I'm wrong. TTFN! DrZaphod [AC/DC] / [DnA][HP] [drzaphod(a)ncselxsi.uucp] Technicolorized

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Info Wanted
by nraizman＠winchester.pp.psc.edu 03 Dec '92

03 Dec '92

Wiggidi-wiggidi-whassup? I'm new here, and , while I can follow the digital money threads, and otehr such things, I am lost when it comes to this PGP and Public Key stuff. Could someone please explain it to me? Thanx a lot! nraizman(a)winchester.pp.psc.edu

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No Subject
by nobody＠rebma.rebma.mn.org 03 Dec '92

03 Dec '92

Here's a new look for electronic cash. Instead of having a bank where people have accounts, have the "banker" be a money changer. He changes Federal Reserve Notes into crypto dollars. Anybody can send him dollars, and include an email address and public key, and he will email them that same amount of electronic cash. Anybody can email him electronic cash, and include a snail-mail address, and he will send them that same amount of U.S. dollars. You don't have a permanent relationship with him, you just use the service when you need to change between electronic and paper dollars. With the Chaum cash that was discussed here a while ago, where you need to "deposit" it right away when you get it, here's what you could do instead. Send it to the money changer, and ask for fresh crypto cash back. It's like you combined a "deposit" with an exactly equal "withdrawal". What you get back is good cash that you can hold or spend as needed. There are no account numbers involved, no demand deposits, no bank account at all. Eric Hughes mentioned demand deposits as defining a bank, so maybe this would be a way around that. -- Mr. Money --

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Re: Suggest splitting things up
by crunch＠netcom.com 03 Dec '92

03 Dec '92

I recommend that we adopt Yim May's idea for how the mailing lists are split up. BTW, if that ever happens, I only want to me on the cypherpunks-technical, and cypherpunks-announce mailing lists. Cheers JD

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