December 2003 - cypherpunks-legacy

Re: Transparent Email
by Alex Strasheim 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Ok, I should start off by saying I'm not sure I followed everything Eric said in his post, so this might not be a great answer to him. My proposal isn't for an all inclusive, everything to all people, security system. It certainly would't preclude people from using other, stand alone systems, from using multiple sets of keys, or whatever else they wanted to do. My posts were predicated on the assumption that transparent encryption and signatures are worthwhile and necessary. By "traansparent encryption and signatures", I mean email systems that work and look pretty much like the programs we're using now -- elm and eudora, for example -- but which do crypto work automatically, behind the scenes. I think we ought to be moving in that direction, for two reasons. The first is that most people -- including most of us -- aren't willing to do much work in order to sign and encrypt our email traffic. If there's any penalty at all in terms of convenience, most people probably won't use a secure system. The second reason is that I believe it's only a matter of time until someone else institutes a transparent, reasonably secure email system. What would happen if Microsoft instituted a secure email system for their online customers, but took control over keys away from users? I think that the result would be that everyone would embrace the new system, because it would be a gigantic improvement over the status quo. We would compare the new system to an idealized vision, in which everyone has total control over their keys, who they trust, and in which law enforcement officials can't retrieve secret keys at will from some central repository. But everyone else would compare the new system to what we have now: an email system which is vulnerable to forging, and which isn't secure enough to transmit credit card numbers. I think that if we can't field an alternative, usable system, something that's practical and easy to use, we're going to lose by default. I'm not under any delusion that what I've proposed is some kind of magic answer. I'm not a heavy hitter, in a technical sense, like Eric, Hal, Tim, and many of the others here are. But at the same time, I think there's some need for compromise. We need a transparent system that can embrace people who aren't willing to put a lot of effort into security, but at the same time is able to accomodate people who want to take more trouble for the sake of their privacy. > This whole area of key distribution has generated much confusion. A > perfect world is described, and then everyone is assumed to > participate in achieving this world. This approach of generality, > however, is notably more complicated than a world where responsibility > for security is partitioned, where each user does not have to worry > about all the possible systemic security issues. I understand this criticism. But if we abandon generality, I don't think we can achieve transparency. And as I said before, I think a transparent system is going to come out on top. It's true that what I proposed is complicated, but a lot of the net is pretty complicated when you take off the lid. I think it could still be made usable. > Proposition: You don't need to be responsible for making sure that the > other person is being spoofed; that's their responsibility. > > A common situation where this proposition makes a significantly > simpler system is exactly in the case described, where you and your > email correspondents wish to exchange keys. Suppose, in addition, > that you two met online and that your only channels of communication > are electronic. The goal here is to create persistence of identity; > identification with a physical body is not needed. Actually, I wasn't trying to identify keys with physical bodies, but rather with email addresses. But the whole point of the system is that there is no need for the two correspondents to worry about exchanging keys: it all happens automatically. People who are doing unusual things, like creating nyms, would of course be free to take unusual actions. > In the PGP case you start with your own key, which you trust, then > look for a chain of signatures to the destination. This chain can be > rather cumbersome to produce. It's overkill, as well, since all you > really needed to know is that the key was not being translated on your > own end. The PGP trust chain largely accomplishes that, true, but not > as simply as possible. I'm not sure I follow the last part of this. > Alternatively, you save the first piece of email that you receive from > your correspondent; it has a digital signature on it. Now _by > whatever means_, you obtain a public key by which to verify that > signatures on email you receive are the same. You yourself need to > ensure that you aren't getting spoofed; you can do this by, say, > having your correspondent send mail to two different locations, or by > using a second channel to obtain the key by, or by using a PGP trust > chain, if one is available. Again, I go back to my goal (which wasn't stated clearly enough in my original posts, to be sure) of transparency, and of trying to get the bulk of day to day email encrypted. > The original model for public key communications seems to have been > one channel with an interposer. The real world is much more > complicated than that. One can obtain good protection, at least as > good as a trust chain, by crossing organizational boundaries. The > argument that trust chains are better because they are cryptographic > carries no weight; the decision at each link to make a signature is of > social, not cryptographic, character. I agree with this 100%. This is part of what I was trying to accomodate. On the low end, we have a default web of trust, which is sort of crummy because it's not terribly difficult to spoof. Cryptographically, it's very sound, but socially, it's quite weak. But my goal was to meet this criticism by making the system open to other webs, and to place as few restrictions as possible on people who want to create and use alternative webs. Those alternative webs could tie email addresses and keys to physical persons, or to nyms, or to anything else they wanted. They could be as rigid or as lax as they pleased. And we as users could decide which webs we were willing to trust. > In particular, the design of PGP that ties key management inextricably > to encryption is bad and will contribute to an inflexibility that will > eventually sink PGP if it is not corrected. Could you elaborate on this? > Perhaps we would have > a default web, which would have everyone's key in it. > > This is a really bad idea. Some "public" keys should not be made > public, but rather revealed only to the correspondent. Forward > secrecy is the reason. If the public key has never been in the > possession of an opponent, and assuming the results of the public key > operation yield little or no information about the modulus, then when > the keys are changed and destroyed, no amount of factoring can find > the private key because the public key isn't around to factor. You could still do this. I did not phrase this well, and I can see where your concern comes from. I have a few nyms, and I don't publish all of my public keys. I didn't mean to imply that all public keys ought to be on the default web. I meant that you ought to be able to get *a* public key for an aribitrary address from the default web. I have used a couple of nyms over the past couple of years, and I haven't published those public keys or tried to associate them with my email adddresses. That would be, as you pointed out, a bad idea. But at the same time, I have a public key for my address here, alex(a)omaha.com, that I want to publish as widely as possible. Right now, it's available via finger at astrashe(a)nyx.cs.du.edu. The system I proposed is just an elaborate (probably too elaborate) substitution for getting the key via finger, with the intention of making transparent secure mail possible. Basically, it comes down to this: in a transparent system, if you want to mail me, somehow your mailer will have to get a copy of my key without your doing anything about it. More importantly, your mailer will have to decide if it should trust the key it retrieves without asking you. Otherwise, it wouldn't be transparent. The problem is: how do we let the machine make this decision on it's own, without imposing a single web of trust on users? That's what I'm trying to get at. > Eric > Thanks for the thoughtful response, I appreciate it. == Alex Strasheim | finger astrashe(a)nyx.cs.du.edu alex(a)omaha.com | for my PGP 2.6.1. public key -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBLtpn7xEpP7+baaPtAQHoIgP/SmOcR2a8PXEwHdF5ROfTmQ2GVxg0ZhlY LYvUKFB+phV7RZAjlP3OCpEjchxTpzaiJFgM4+wtKulrD0ZdGfyF6iGM+K8OTAql lWMfJ25/AvfTlqfBlZ0TAX4hkEWF5r3D65TpncgR7VOF8XErmFPPEvVCvZhx6Rd/ koZmgdTIoXg= =vJqj -----END PGP SIGNATURE-----

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Re: A possible solution
by Alex Strasheim 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- > The use of cryptography makes it virtually impossible to know anything. > If everyone used to PGP to communicate. I mean everybody in the whole > entire world. There would be no possible way to ever know what is going > on. What about signatures? You know (or at least you could) that I wrote this note, thanks to PGP. Crypto doesn't just hide things, it can establish indelible trails as well. In this particular instance, PGP has added to what you know, because the signature has added information to the post. Crypto isn't just about secrecy: it gives us a set of tools that allow us to have a great deal of control over how much of a trace our actions will leave, and who is able to see that trace. == Alex Strasheim | finger astrashe(a)nyx.cs.du.edu alex(a)omaha.com | for my PGP 2.6.1. public key -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBLtpzdxEpP7+baaPtAQEL2gP/afzRoPmDWYKWdOl7u4O4qDgB8QiQjzla RrKShPfmXK0U06eU5Wran1VYKYOaGkoRhQbZQXQ8T33sbFNHWKYPcDcYpXT6kkqu dT/AHcp/wuCYp0oeb65qYhuiemus0cFPWzfPujOkwKnm8r57lz9S8YVeSMHQzWrv glLORANPoO0= =r1q5 -----END PGP SIGNATURE-----

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Forwarded message from comp.internet.nethappenings
by jgrubs＠voxbox.norden1.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Path: voxbox!hypnos!malgudi.oar.net!caen!zip.eecs.umich.edu!newsxfer.itd.umich.edu!gatech!howland.reston.ans.net!usc!news.cerf.net!noc.cerf.net!news-mail-gateway From: sackman(a)plains.nodak.edu (Gleason Sackman) Newsgroups: comp.internet.net-happenings Subject: WWW> Digitale Burgerbeweging Nederland DB.NL (fwd) Message-ID: <Pine.3.89.9411271743.D13938-0100000@plains> Date: 28 Nov 1994 06:57:26 -0800 Sender: daemon(a)CERF.NET Distribution: world Organization: CERFnet Lines: 34 Approved: usenet(a)noc.cerf.net NNTP-Posting-Host: noc.cerf.net - ---------- Forwarded message ---------- SENDER: mwharing(a)cs.vu.nl (Haring MWA) Subject: ORG> Announce: Digitale Burgerbeweging Nederland DB.NL Date: Wed, 23 Nov 1994 19:38:20 GMT =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Digitale Burgerbeweging Nederland ..sticking up for the interests of digital citizens... On Saterday 15 October the dutch db.nl (digitale burgerbeweging nederland) organization was founded in Amsterdam. Some of our items are: o digital democracy, citizens' rights such as freedom of speech, protection of privacy and involvement in policy making. o socially valuable applications of information and communication technology o an accessible and user friendly digital public network The organization was founded in reaction of government plans to ban cryptografy, and regulation wich would forbid public libaries to lend electronic information. For more information you can check out our web-pages. WWW: http://www.xs4all.nl/~db.nl fax: +31 20 6239761 phone: +31 20 6200174 e-mail: db.nl(a)xs4all.nl snail-mail: P.O. Box 18624 1001 WD Amsterdam =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBLto+5t74r4kaz3mVAQHM9AP+KVFGtjrTPAC3ep8xbbxUM3+woy9i+43l 9ZZTNXVXHjUoymlvpCpooJnP/qp4+KKIuZIjqz7clhCJpU/hH3K8Yd1ROTyVyT50 ou8CUXod4j0vYq2O1HL7nZnkV6PVqGDcDtlfE1nOVtWyYjuoy3nk1+QST3mXNny3 LgL/wDP3ezo= =s1H2 -----END PGP SIGNATURE----- ... "The greatest dangers to liberty lurk in the insidious encroachment of men of zeal, well meaning but without understanding." - Justice Louis Brandeis -- jgrubs(a)voxbox.norden1.com (James C. Grubs, W8GRT) Voxbox Enterprises, 6817 Maplewood Ave., Sylvania, Ohio 43560-1956 Tel.: 419/882-2697

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RE: Cash
by nobody＠jpunix.com 17 Dec '03

17 Dec '03

>On Fri, 18 Nov 1994 wcs(a)anchor.ho.att.com wrote: > >> Hasn't really provided it for quite a while, as long as there's an >> infrastructure to track serial numbers (you've presumably noticed that >> each bill a unique serial number, except for counterfeits and maybe >> printing glitches.) > >And every bill that passes through my hands (of course not the ones I >handle at work, I'm talking personal here...) gets the serial # >overwriten in heavy black marker. > >Happy Hunting, -Chris. I went to a GSA auction and picked up 3 very nice U.S. Gubment surplus paper shredders. They shred into very fine particulate that makes great fire starting material for the fireplace. I run everything with my name, address, etc., thru it so that *none* of my trash is identifiable. How's that for paranoid :>

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MIME meme continues... New internet drafts
by Eric Blossom 17 Dec '03

17 Dec '03

[ Perry, hit "delete" now... ] Here are a couple of more internet drafts relevant to secure email. ftp://ds.internic.net/internet-drafts/<filename> Title : Security Multiparts for MIME: Multipart/Signed and Multipart/Encrypted Author(s) : J. Galvin, S. Murphy, S. Crocker, N. Freed Filename : draft-ietf-pem-sigenc-02.txt Pages : 10 Date : 11/23/1994 This document defines two new content types for specifying the application of security services to MIME message bodies. MIME, an acronym for "Multipurpose Internet Mail Extensions", defines the format of the contents of Internet mail messages and provides for multi-part textual and non-textual message bodies. The new content types are subtypes of multipart: signed and encrypted. Each will contain two body parts: one for the protected data and one for the control information necessary to remove the protection. The type and contents of the control information body parts are determined by the value of the protocol parameter of the enclosing multipart/signed or multipart/encrypted content type, which is required to be present. Title : PEM Security Services and MIME Author(s) : S. Crocker, N. Freed, J. Galvin, S. Murphy Filename : draft-ietf-pem-mime-07.txt Pages : 34 Date : 11/23/1994 This document specifies how the services of MIME and PEM can be used in a complementary fashion. MIME, an acronym for "Multipurpose Internet Mail Extensions", defines the format of the contents of Internet mail messages and provides for multi-part textual and non-textual message bodies. PEM, an acronym for "Privacy Enhanced Mail", provides message authentication/integrity and message encryption services for Internet mail messages.

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RE: Cash
by merriman＠metronet.com 17 Dec '03

17 Dec '03

>>On Fri, 18 Nov 1994 wcs(a)anchor.ho.att.com wrote: >> >>> Hasn't really provided it for quite a while, as long as there's an >>> infrastructure to track serial numbers (you've presumably noticed that >>> each bill a unique serial number, except for counterfeits and maybe >>> printing glitches.) >> >>And every bill that passes through my hands (of course not the ones I >>handle at work, I'm talking personal here...) gets the serial # >>overwriten in heavy black marker. >> >>Happy Hunting, -Chris. > >I went to a GSA auction and picked up 3 very nice U.S. Gubment surplus >paper shredders. They shred into very fine particulate that makes great >fire starting material for the fireplace. >I run everything with my name, address, etc., thru it so that *none* of >my trash is identifiable. >How's that for paranoid :> > How much would you want for one of them, assuming there's one for sale? Dave "Getting more paranoid by the minute, sometimes" Merriman - - - - - - - - - - - - - - - - - - - - - - - - - - Finger merriman(a)feenix.metronet.com for PGP public key and fingerprint. PGP encrypted Email welcome, encouraged, and preferred. "Those who make peaceful revolution impossible will make violent revolution inevitable." John F. Kennedy

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Secure EDI over Internet
by xpat＠vm1.spcs.umn.edu 17 Dec '03

17 Dec '03

Summarized from PC Week, Nov 28th, page 44: -begin- Premenos Corp now testing product to foster Electronic Data Interchange transactions over the Internet. Technology licensed from RSA Data Security Inc provide the security features, encryption, authentication, and guaranteed message delivery. Carl Redfield, VP of manufacturing for Cisco Systems Inc, was quoted as saying, "Security is the most important factor to us, as it is now, anyone could intercept messages off the Internet." Cisco is involved in testing the new product. The Premenos suite will be available first quarter 95. Pricing not set. These phone numbers were given for more info: Premenos (800) 426-3836 Cisco (800) 553-6387 -end- regards, -pd-

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Re: How to disable telnet to port 25
by wcs＠anchor.ho.att.com 17 Dec '03

17 Dec '03

> The Al Capone of the Info Highway says: > > A while back, there was a discussion about how to fake a from > > address by telneting into port 25 in a site. Many people discussed > > the pro's and cons, but I wanted to know if anybody knows of a way > > to stop people from getting in there to send the message in the > > first place. > Sure. Turn off mail to your site. You don't have to go quite that far (almost, but not quite :-) You can do things like only accept your incoming mail via uucp, which has a whole different set of holes and limitations, but which is supported by a number of the major network suppliers. If you're on dialup access anyway, uucp is fine. If you've got a real IP feed, uucp-over-tcp has slightly more authentication than smtp, and can turn off anonymous access, but that basically means you're transferring your trust to your MX forwarder's security system, which presumably still speaks port 25. Bill

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UN_nab (Re: an96489)
by John Young 17 Dec '03

17 Dec '03

Responding to msg by an96489(a)anon.penet.fi () on Tue, 29 Nov 1:8 AM >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. Dear an96489, Penet.fi warning jams lob of UN_nab. Kiss twice wid nice nym-id.

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We really _aren't_ paranoid :)
by Johnathan Corgan 17 Dec '03

17 Dec '03

Just in case anyone didn't catch this in the newsgroups: From: dcd(a)se.houston.geoquest.slb.com (Dan Day) Newsgroups: talk.politics.crypto,alt.privacy,alt.security.pgp Subject: Re: Mandatory Key Escrow: Goodnight! Date: 28 Nov 1994 19:02:31 GMT Organization: GeoQuest System, Inc. Houston Lines: 29 Message-ID: <3bd9g7$1fc(a)sndsu1.sinet.slb.com> In article <3b655b$rne(a)eis.calstate.edu> jomcgow(a)eis.calstate.edu (John S. McGow an) writes: > >It is frightening how the power to regulate "interstate commerce" has >been used as a justification for the constitutional authority of the >federal government to intercede in so many things. The good news is a few justices still seem to have their heads on straight: Item from AP: It seems that in urging the Supreme Court to reinstate a federal-level ban on firearms within 1000 feet of schools (the 1990 Gun-Free School Zones Act), the Clinton administration argues that the national economy is adversely affected by gun-related violence at schools. Therefor, the reasoning continues, Congress was authorized to institute the ban under (you guessed it) the Interstate Commerce clause of the Constitution. Said Solicitor General Drew S Day III, "This is not about just regulating guns. Congress is concerned with this impact on the national economy." Asked Justice Ruth Bader Ginsburg, "Is there any violent crime that doesn't affect interstate commerce under your rationale?" Ginsburg later asked Days to cite an example of a law which Congress would NOT have the authority to enact under the Interstate Commerce Clause. Interjected Justice Scalia, "Don't give away anything here. They might want to do it." -- ----------------------------------------------------------------------- Johnathan Corgan "Violence is the last refuge of the incompetent" jcorgan(a)netcom.com -Isaac Asimov PGP Public Key: http://www-swiss.ai.mit.edu/~bal/pks-toplev.html Or send email to: pgp-public-keys(a)pgp.ai.mit.edu Subj: GET jcorgan -----------------------------------------------------------------------

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