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MEETING: Cypherpunks UK (2nd; last announcement)
by whitaker＠eternity.demon.co.uk 05 Jan '93

05 Jan '93

-----BEGIN PGP SIGNED MESSAGE----- 2nd Meeting, Cypherpunks UK - --------------------------- Chris Tame, of FOREST and the Libertarian Alliance, has generously offered the use of the meeting room at his offices for our gathering, Sunday, 10 January 1993, from 1300 onwards, at: FOREST 4th Floor 2 Grosvenor Gardens London SW1W 0DH 071-823-6550 This is just around the corner from Victoria Station, at the end of the mansion block near Hobart Place. There's a dark green cabbie shelter across the street from the entrance, and some British Telecom payphones. Can't miss it, really. However, if you have trouble, call the telephone number above, or call my pager, on 081-812-2661. If it helps, we're in the direction of Buckingham Palace, which is (very) partially visible from our windows. If you wish to attend, you should bring a 3.5" DOS-formatted diskette (sorry! My UN*X machine is an Intergraph workstation, and I can't use it for crypto) with a copy of your PGP 2.0+ public key. I'll sign it there. Mac users: if you don't have Apple File Exchange (what!?), I'll be extra nice and take your keys anyway ( ;-)) for AFE conversion on my IIcx. Not to fear. It might not be a bad idea to copy your public key on each of several diskettes, so you've got a copy to distribute to each of the others. Don't trust me to copy *your* key to others! As a matter of fact, as there are plenty of power points in the meeting room, you should bring your laptop, and/or a desktop PC: when someone hands you a disk-with-key, you can sign her key, and hand her back her diskette, with your own pubkey added. [Note to the novice: don't hand another person your secret key... the one named secring.pgp. Read the documentation.] This should be a lively meeting. Among the topics likely to be discussed are: o The proliferation of public key cryptography in the U.K. o The local development of anonymous remailers and a proposed automated public key repository at Demon Internet Systems o Electronic networking/email security for the novice o Pro-active proliferation of PGP 2.1+ to interesting European, African, and Asian sites - ftp placement - BBS distribution - sneakernet across borders o The use of HPACK in securing local file installations .. and much more! Mark Turner, from Demon Internet Systems, is likely to be on hand to demo DIS for non-DIS users. We've set up our own local, high-quality newsgroups: demon.security demon.security.keys and established the /pub/pgp and /pub/ibmpc/pgp archives on gate.demon.co.uk (expanding recently to include all versions of PGP, and interesting related files). Hope to see you there! Semper vigilans, -----BEGIN PGP SIGNATURE----- Version: 2.1 iQCVAgUBK0lmwYTj7/vxxWtPAQFtVQQAna8vfz6LqC5J5fhlgE1FB+m4GpkvU4o9 HrpFd5NKTc+JrKZEuv/sEDbJvXScc5N38n9KCyIEKdPEUxsjSA58CffcLLEW4xnb w3zAIMyr3wdsD0sxw0gqSi3sx6MbGP5fXwbUb+LyNJzCvpzt3MLYA5tYWZkvIbl9 ONV1PIPtB60= =8qA3 -----END PGP SIGNATURE----- Russell Earl Whitaker whitaker(a)eternity.demon.co.uk Communications Editor 71750.2413(a)compuserve.com EXTROPY: The Journal of Transhumanist Thought AMiX: RWHITAKER Board member, Extropy Institute (ExI) ================ PGP 2.0 public key available =======================

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Re: purloined letter
by wcs＠anchor.ho.att.com 05 Jan '93

05 Jan '93

The hiding-data-in-bogus-text system that Phil referred to is Peter Wayner's Mimic functions, which let you represent data using a Huffman code or context-free-grammar set of productions that matches innocuous text. The examples in the paper used baseball game radio narration (hiding a message "Paul is dead" :-) and political speeches by Mr. Neil Kinnock, the raving Labour Party honcho whose speeches were plagiarized by Joe Biden. (Biden, btw, was a nice guy when he was elected to the Senate at age just-under-30, but he's apparently gone Big Brotherish as he's aged. I'm not bothered by one politician borrowing another's speeches, but stooping to Neil Kinnock's syrupy ranting is a bit much :-) The papers on the mimic functions are in ftp.cs.cornell.ecu, under /pub/wayner/Mimic. There are also a couple of papers on building a highly parallel des-cracker out of content-addressable memory, Until encryption becomes widely used, if yuo want to hide encrypted data, mimic functions or low-bits-of-gifs are good ways to go. Bill Stewart

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RFC-822 header processing in perl
by eric＠parallax.com 05 Jan '93

05 Jan '93

I've written a perl script to parse RFC-822 style headers. It was a good deal harder than I had thought it would be. Since it's over 300 lines (with comments) I won't post it, but will mail it to anyone who wants to play with it. It has the following features: Doesn't touch anything unless you ask it to. Leaves the ordering and whitespace/folding of header lines unchanged. Allows you to replace any header line (which appears only once) with an arbitrary value, which is appropriatly folded on output. Allows you to delete any header line, or add a header line to the end of the header. These are special cases of replacing a header line. Allows you to access the value (stuff after the :) of any header line. Given a list of addresses, returns an array of canonicalized addresses. The last item is the hard part. It correctly parses the sample addresses in the RFC-822 paper, as well as some really gnarly looking junk that I threw at it. It correctly handles the various types of quoted strings, and backslash quoting, not splitting addresses at quoted commas. It removes nested comments from addresses. It deletes the group name from a list of addresses without screwing up quoted colons. It should be useful as a first step in alias processing. That's what I'll be adding next, when I figure out exactly how I want to do it. -- eric messick eric(a)toad.com

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Re: purloined letter
by karn＠qualcomm.com 05 Jan '93

05 Jan '93

A couple of years ago somebody posted some clever programs to sci.crypt that hid arbitrary (cipher)text in seemingly innocuous "plaintext". You had two options: plaintext that looked like a running commentary on a baseball game (with the ciphertext encoded in the choices of names of players at bat, the sequence of balls and strikes, etc) or plaintext that looked like the writings of a particular legal scholar (I think). I don't remember his name, but he was chosen because Senator Joseph Biden of Delaware plagairized his works during law school, and Biden had recently introduced S.266 with the now-infamous "resolution" against cryptography. A nice touch. :-) Another approach to this problem is this: if you can't make the needles inconspicuous by themselves, generate some big haystacks to hide them in. I.e., write a program that produces bogus PGP "messages" and execute it frequently to produce background traffic. I wrote a first-order bogus PGP message generator and posted it to sci.crypt two weeks ago. I say "first order" because it looks like a PGP message to the naked eye, but is clearly invalid when fed to PGP - I didn't bother generating correct checksums on the ciphertext. The ideal bogus message generator would produce a message indistinguishable from a real PGP message encrypted with an unknown public key, or perhaps with a known public key chosen at random. Anybody want to write this? Phil

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Re: RE: Acceptance of Keys
by Matt Willis 05 Jan '93

05 Jan '93

From: "Karl L. Barrus" <barrus(a)tree.egr.uh.edu> writes: > You posted some very good questions. The reason why it is >"unacceptable" to accept keys electronically is that you may be >vulnerable to spoofing. Okay, in reality, you have to realize that >attacking cryptographic protocols is a paranoid view of things, and >that you may not be attacked, but... if you send your public key to >somebody, it could be possible for someone to eavesdrop, grab your >key, substitute their own, and send that one along. Then when someone >responds to "you", the eavesdropper could read the message, re-encrypt >it with the public key they stole, and send it along to you. Then, >you don't even know you are the victim of eavesdropping. But we both call the same system (at least the people I x-change keys with) usually mindvox or a private system with a respected name... and in the case of Minvox, we do a DCC on IRC... straight person-to-person... to be eavesdropping... one, they'd have to tap my line, heavy equipment needed to tap a 16.8k HST v.42bis connection, seeing as I pretty much max out a phone line and HST's are really picky... or two, they'd intercept a DCC on the IRC at berkeley... but that's a 57.6k connection... however, that does seem possible... does anyone have any suggestions on how to make e-transfers of keys more secure, because, besides snail-mail (which would please the feds a lot) I have no other way of getting my key to them... > Anyway, it all boils down to validating the keys you receive. >Which makes it tough unless you can meet people face to face. >However, the latest version of pgp contains an option which computes >the md5 hash of your public key - which allows you to call someone, >and read each others hashes, thus completing the verification over the >phone. Of course, now you have to worry about receiving their correct >phone number... :-) geez, I didn't know it was this complicated... if someone screws with the key, it just doesn't decode, correct? nowadays, with MNP and ARQ-retries and all of our little .bis buddies, not to mention the CRC's in transfer protos, wouldn't that make an error in transfer EXTREMELY remote... so the only other way'd be tampering and even then it just wouldn't decode, so what... you get the key again... but I oversimplify the situation, I guess... Oh, and I know this is going to make me sound like a complete idiot in front of my peers, but I've always did straight tranfers of keys... how do you put ascii keys into your keyring? I can't seem to make MacPGP do it... sniffle... and if ihe reason I can't decode the key is due to an error in transmission, forget this entire message... +-------Matt-Willis--------------------------------+ | Matt Willis ASTMWILL(a)STETSON.BITNET | elsewhere: | Matt Willis Head of the Underground | mwill(a)mindvox.phantom.com | Matt Willis Robotech PBM List | +-------Matt-Willis--------------------------------+ "Absolutely alone in awareness of the mechanism." -Agrippa by WG

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Hiding PGP code
by Matt Willis 05 Jan '93

05 Jan '93

Peter Breton <pbreton(a)cs.umb.edu> writes: > In using encrypted communications, how does one avoid the problem of >calling attention to the message BECAUSE it is encrypted? "If he went to >the trouble of coding it, there MUST be something in there!!" Granted that >if everyone begins encrypting, this problem will vanish... are there >practical solutions in the meantime? (eg, Codes that look like plaintext?) Here's an interesting solution... You can program a message filter to add extract letters to each PGP character to make it a word. I'm sure you could find any database of words and have it randomly make first letters... it'd be pretty simple... and then the receiver would just take every letter followed by a space... and if you wanted to be ultra-sneaky (who, us) you could have null words that change conditions in the letter... like switching to the second letter in the word, or skipping the next word altogether... but what to do with no-letter PGP codes... ok, the first TWO letters of the word indicate a character... sort of like a byte... hey, I think I might just write this sucker... Code will follow! carpe crypto +-------Matt-Willis--------------------------------+ | Matt Willis ASTMWILL(a)STETSON.BITNET | elsewhere: | Matt Willis Head of the Underground | mwill(a)mindvox.phantom.com | Matt Willis Robotech PBM List | +-------Matt-Willis--------------------------------+ "Absolutely alone in awareness of the mechanism." -Agrippa by WG

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Re: Remail addresses...
by Hal 05 Jan '93

05 Jan '93

-----BEGIN PGP SIGNED MESSAGE----- From: edgar(a)spectrx.Saigon.COM (Edgar W. Swank) > > Anon-To: <next destination> > Encrypt-With: <some DES or IDEA key> > > I'd like to point out that the "-ca" function of PGP could be used > to perform this function if Encrypt-With: specified a PGP pass-phrase > rather than a direct key. This sounds like a good idea. The user would have to have some scripts to decrypt incoming anonymous-address messages using this pass phrase (or some sequence of pass phrases if more than one remailer was used for the anonymous address). > I'd also like to suggest that the message- > body to be encrypted require heading and trailing delimiters such as: > > -----BEGIN MESSAGE BODY----- > -----END MESSAGE BODY----- > > Note delimiters would not be part of message body and would not > be encrypted. These anonymous addresses do need a distinction between the "message address" (or "envelope") and the message body. The anonymous address gets decrypted at each step, and the message body gets encrypted at each step using the scheme above. But Eric Hughes pointed out that we already have such a distinction in the RFC822 message headers vs body. We should use that existing structure rather than try to create our own. That means that anonymous addresses should be designed to fit into mail headers. Unfortunately many mail agents make this difficult or inconvenient right now, but perhaps that is an area where we could make some improvements. In this model, we would not need message body delimiters, since mail already has its message body delimited distinct from its headers. If we do process the message body with encryption at each stage, I do have an idea which could be useful. If the body which is being encrypted is already in the format of an ASCII-encoded message using the standard RFC822 encryption used in PGP, RIPEM and PEM, then rather than just encrypting it it could be de-ASCII'd, then encrypted, then re-ASCII'd. This would keep it from increasing in size by a factor of 4/3 at each encryption step. Hal -----BEGIN PGP SIGNATURE----- Version: 2.1 iQCVAgUBK0kHvKgTA69YIUw3AQHBuwP/ekp1feh06tLHwxws49DE3wVxnu/36Yg7 oW2l43n3llgRJC+r/KYJ2+5LTG0/f1Ib/R8c4qxUJzZeCj7zABSdJ6KSwIlwmfP6 Djz0vOBnife6CvhQRi+T/8NuFqFIzlxO1vK+7tG9KWshxP+7AMayGOLuY0pOTREX 7brcJHnn7Mg= =9Uss -----END PGP SIGNATURE----- Distribution: CYPHERPUNKS >INTERNET:CYPHERPUNKS@TOAD.COM

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Re: Return addresses
by edgar＠spectrx.Saigon.COM 05 Jan '93

05 Jan '93

Hal Finney wrote here on Dec 30: Chaum's idea was that the message contents would be encrypted at each step, as Eric suggests, but Chaum would have the encryption key be part of the anonymous address, created by the same person who made the anonymous address. The idea would be, after decrypting the incoming message, the remailer would see something like: Anon-To: <next destination> Encrypt-With: <some DES or IDEA key> It would then encrypt the message "contents" (but not the "envelope", as Eric points out) using the specified key. When the owner of the anonymous address received the message, he would decrypt it using the chain of "Encrypt-With" keys that he put into the anonymous address. I'd like to point out that the "-ca" function of PGP could be used to perform this function if Encrypt-With: specified a PGP pass-phrase rather than a direct key. I'd also like to suggest that the message- body to be encrypted require heading and trailing delimiters such as: -----BEGIN MESSAGE BODY----- -----END MESSAGE BODY----- Note delimiters would not be part of message body and would not be encrypted. -- edgar(a)spectrx.saigon.com (Edgar W. Swank) SPECTROX SYSTEMS +1.408.252.1005 Silicon Valley, Ca

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Acceptance of Keys
by Matt Willis 04 Jan '93

04 Jan '93

<As excerpted from Julf (admin(a)anon.penet.fi) >Richard Childers writes: > >> It is the user's job to hide his or her identity, but it should not >> be the programmer's responsibility to anticipate the user's failure >> to think at all. Someone who uses these tools without understanding >> the principles upon which they are founded - such as people whom >> accept keys from individuals whom are only electronically known - >> will quickly founder upon their own, um, state of stupor, and one >> should not undertake to protect them from this, as what you are pro- >> -tecting them from, in reality, is the opportunity to learn from >> their mistakes. As wary as I am of expressing my ignorance, I'll give it a shot... I'm new to the Cypherpunks list and I'm just curious, is it going against the principles of PGP to "accept keys from individuals whom are only electronically known"? (if so, I guess I'm in a state of stupor) Most of my dealings on the internet are internet-exclusive, that is, I never meet the people with whom I communicate. With the exception of some locals, computer social life in FL, USA is pretty non-existant. I wish my communications to be secure and I believe that PGP is the best way and I will never have the opportunity to meet the people I talk to in Kansas or in New York (both places, I hope I never visit). If meat-relations are the only secure way I'm supposed to communicate, then I guess I'll have to use carrier pigeons. :) DISCLAIMER: Of course, I could be taking this TOTALLY out of context, and in that case this message should read: Hey, I really like this list... It's intellectually stimulating and a clearly positive influence on my life. How's the weather in Europe? I'm not trying to be argumentative, I just have serious questions about the keeping of public keys... here's another one... couldn't we assign one at birth... it'd be better than a social security number (dunno what you use in Europe), but a whole lot harder to remember... ALSO: We Mac users are wondering when MacPGP 2.1 will be out? Anyone have any contact info? thanks for reading my words. +-------Matt-Willis--------------------------------+ | Matt Willis ASTMWILL(a)STETSON.BITNET | elsewhere: | Matt Willis Head of the Underground | mwill(a)mindvox.phantom.com | Matt Willis Robotech PBM List | +-------Matt-Willis--------------------------------+ "Absolutely alone in awareness of the mechanism." -Agrippa by WG

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Re: The Need for Positive Repuations
by hughes＠toad.com 04 Jan '93

04 Jan '93

--------------------------- Original Message --------------------------- You sent this to cypherpunks-request and not to cypherpunks. Eric ----------------------------------------------------------------------------- Return-Path: <@YaleVM.YCC.Yale.Edu:KL62@MARISTB.BITNET> Date: Fri, 18 Dec 92 15:18:35 EST From: "Ryan, Edmund J" <KL62%MARISTB.bitnet(a)YaleVM.YCC.Yale.Edu> To: <cypherpunks-request(a)toad.com> Subject: Re: The Need for Positive Repuations In-Reply-To: In reply to your message of FRI 18 DEC 1992 11:45:55 EST > Indeed, in the long run, when there are billions of people in the nets, > even UseNet newsgroups devoted to people who use musical instruments as > sex toys would have thousands of posts a day because given billions of > possible subscribers, finding a few tens of thousands with a particularly > obscure interest wouldn't be hard. Thus, in the long run, the nets will move > to "closed" newsgroups and mailing lists in which to be a subscriber one > will have to be explicitly subscribed to a list and will only be able to > read with one's private key and post by digitally signing messages. In such > an environment, anonymous abusers will simply be incapable of annoying people. Well there won't be a complete movement in that direction. The set up of the list may differ. Some lists may be open to all to read but open only to subscribers to post. Some lists may be the other way around. (Can't think of an example, but there may be one out there.) By the way, I've never really seen too many abusive postings on the Usenet groups I frequent.It doesn't seem to be a problem. Just my opinion. > A weak version of this exists already in the Extropians mailing list, which > considers itself to be a closed list. The list is governed by a privately > produced legal code (its in some ways a test of anarchocapitalist legal theory > and since the adoption of the code, we've had a reduction of flaming by > a large factor even though we've seen a three fold increase in list size. > The content is improving because people know that sanctions will be applied > for flaming and that they can actually be kicked off the list, and that being > kicked off is meaningful. In the long run, all serious discussion groups > will likely evolve in this direction, with the lists being closed to explicit > subscribers and with meaningful sanctions like ostracism being applied to > people that behave in an antisocial manner. Such lists have little reason > to fear people hiding behind cloaks of anonymity. With digital signatures, > even the anonymous can develop meaningful reputations and can be sanctioned > for failing to live up to those reputations. > > Perry Again, there will always be the fun of watching people flame. Virtually, Edmund J. Ryan ------------------------------------------------------------------------ - Edmund J. Ryan C.I.S. Major Extropian - - KL62@MARISTB C.S. Minor Libertarian - - "Insert your snappy quote of the day." - ------------------------------------------------------------------------ ------------------------------------------------------------------------ - Edmund J. Ryan Major: Computer Information Systems - - KL62@MARISTB Minor: Computer Science/Business - - Marist College Political philosophy: Libertarian - - Poughkeepsie, NY Extropian - - - - "Replace taxpayers with shareholders, - - regulators with customers: privatize!" - ------------------------------------------------------------------------

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