- cypherpunks-legacy@lists.ogf.org

CYPHER: Problems with pgp2.2 ELM scripts?
by R.Tait＠bnr.co.uk 19 Mar '93

19 Mar '93

-----BEGIN PGP SIGNED MESSAGE----- Hi all, Has anyone apart from me experienced problems with Vesselin's perl scripts for ELM that came bundled with pgp2.2? I'm running ELM 2.4 pl21, on a Sparc IPX, and basically, sometimes morepgp works, and sometimes it doesn't. mailpgp is proving fine. Now, I'm no perl wiz, so I can't really dive in and fix it, nor am I asking for someone to fix it (unless they want to), but it would be nice to know that it's just not my utter ineptitude... ;=) - -- Rick M. Tait Bell Northern Research (Europe) Tel: +44-81-945-3352, Fax: +44-81-945-3352 Network Management Systems <PGP 2.2 public key available on request> New Southgate, London. UK email: ricktait(a)bnr.co.uk || gomez(a)cix.compulink.co.uk || ricktait(a)bnr.ca -----BEGIN PGP SIGNATURE----- Version: 2.2 iQCVAgUBK6ixmdIfJtINuGaBAQGjWgP/R67RPs45OJLD65ZqtJVKOLpYrwaLQ8cT GOo9Ek9P2flywLt30U+h6/6JOmNCI9UhzeDUKpvnymk4OyReHnayDvtVqjM9c4AL dj+xez2wjFHgxvpOfaAVNGvLlYj5BiVu+D5S3w9laxczT0MvSDTfFhwJFEP+VWxE NbkeIjN4FrI= =/qoI -----END PGP SIGNATURE-----

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Anonymity in the real world
by Arthur Abraham 19 Mar '93

19 Mar '93

Re: Anonymity in the real world John Gilmore writes: >The person who wrote this stuff hasn't thought it through. Any of these >things can and do happen right now over the telephone (anonymously) >and through postal mail (anonymously). Somehow, society has not fallen >into anarchy because anyone can drop a letter in a mailbox. Why not? > >(pause here and actually think about it...) A lot of the stuff that appears on this list appears to come from people glassey-eyed hypnotized by the "power" of the internet, as if society had suddenly started behaving differently because we now type over our telephones. Actually, this is an abuse of a technology, since it's much quicker, and accurate, to talk over a telephone -- greater bandwidth, for those who insist on describing people in mechanical terms. If all our desks were in the same large room, each in its own little cubical, and we communicated by writing on pieces of paper and magically passing them around, the effect would be much the same as the internet -- except that the internet saves about a forest per gigabyte. For those who insist the difference is that the internet is "free", let them remember that each person has either purchased or is paying rent for their desk, but some of the rent is in the form of labor, etc. In this large room there are many people I have never meet, but who still send me pieces of paper. The pieces of paper have names on them, but since I have never meet the person who sends me a particular piece of paper, the names mean nothing; the sender is Anonymous to _me_, though I hope they have some friends. If I get enough pieces of paper from the same person, I eventually come to recognize the name, and form some expectations of what they have written on the piece of paper; then the person is a Pseudonym to _me_, since I still have not yet met that individual. This does not seem to be a lot to argue over. Suppose I now receive a piece of paper that says "Your doom is coming! You have been using my pieces of paper to blow your nose on! I cannot let this insult go unpunished: You will die at midnight!" I could think: well, it's just a piece of paper, there's no particular reason to be afraid of it. I could think: it's a large room, and this sender will have trouble finding me, so my doom will never arrive. I could think: as with most of the people in the room, this sender has never meet me, so my doom will not be able to recognize me. But what do think is: I will arrange to have a policeman at my desk at midnight, since it is still the real world. This is my experience of the internet. ************************************** bandwidth expander: :-) starts here ************************************** Now I will tell a fable about the old use of the telephone. Once upon a time, in a kingdom by the sea, the phone company (TPC) wanted to sell the peasants' phone numbers to anybody the peasants would call. It was an easy way to make gold. TPC said over and over again that peasants really enjoy doing this. However, the peasants didn't want to join in the fun, and insisted on having an option of deciding when TPC could sell the phone numbers -- a cypherpunk might say the peasants wanted to retain control of their anonymity. TPC saw that most of the peasants wouldn't release their phone numbers, and so there wouldn't be enough gold in it, and decided not to offer this wonderful service, and the peasants lived anonymously ever after... ...for about three days until the all the people in the kingdom, suddenly drunk on the newfound anonymity, completely overloaded and destroyed the phone system, by all lifting their phones at once, to place bomb threats. -a2.

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Re: Cypher:Subject naming- SUMMARY
by Jim C 19 Mar '93

19 Mar '93

Ok, here's a summary of replies regarding sorting of mail by To: fields, or more in general, grouping all list mail together by mailing list. Thanx to all who responded. As you can see, there are a variety of ways to approach this problem. All of these replys were posted to Cypherpunks already, so re-posting is kosher. I've cut out the extra header stuff and the PGP signatures, and edited the messages for brevity. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> From: nowhere(a)bsu-cs.bsu.edu (Chael Hall) Subject: Re: Cypher: Subject naming proposal To: collins(a)socrates.umd.edu (Jim C) Cc: cypherpunks(a)toad.com >Can I suggest that any messages posted to cypherpunks start with "Cypher:" >in the subject line? The mail from this list is getting mixed in with all >my other mail, cause my newsreader (elm) can't sort on "To:" fields. > Does anyone else have this problem? Does this idea seem reasonable? >JIm C. I use the following .forward file to make slocal "sort" my mail based upon the contents of the .maildelivery file below. -- $HOME/.forward -- | /usr/lib/mh/slocal -user nowhere <EOF> You should use something like the following .maildelivery file to tell slocal where to put the messages. -- $HOME/.maildelivery -- # # field "pattern" action "command" # To "cypherpunks(a)toad.com" file ? Mail/cypherpunks This will file messages directed to cypherpunks to a file in your Elm mail directory, but leave all other messages untouched. You have to then choose the folder "=cypherpunks" to read those messages. NOTE: You need to change the path of slocal to the appropriate path for your system. You can find it with the whereis -b command or the find utility. Am I forgetting anything? Chael Hall -- Chael Hall nowhere(a)bsu-cs.bsu.edu, 00CCHALL(a)BSUVC.BSU.EDU (317) 285-3648 after 5 pm EST >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> From: Crys Rides <crys(a)cave.tcp.COM> Subject: Re: Cypher: Subject naming proposal >>>>> On Thu, 18 Mar 93 10:39:46 EST, nowhere(a)bsu-cs.bsu.edu (Chael Hall) said: Hall> I use the following .forward file to make slocal "sort" my mail based Hall> upon the contents of the .maildelivery file below. [snip] Hall> NOTE: You need to change the path of slocal to the appropriate Hall> path for your system. You can find it with the whereis -b command or Hall> the find utility. Am I forgetting anything? Erm, only that this apparently appears to pretty much _require_ switching mailreaders to MH. A more transparent solution can be achieved with the 'procmail' package, available from any comp.sources.misc archive. This package allows rule-based filtering on message content, size, and other factors, and can be installed workably with most mailreaders to my knowledge, without requiring much effort. Crys Rides >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >From wimsey.bc.ca!markh(a)wimsey.com Thu Mar 18 13:: Cypher: Subject naming propos al There's a program called "filter" (which I think is part of the elm distribution) that I use to automatically route messages from different mailing lists to separate folders, which can then be read at leisure. Very handy! derek >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> To: Brad Huntting <huntting(a)glarp.com>, Jim C <collins(a)socrates.umd.edu> Subject: Re: Cypher: Subject naming proposal Cc: cypherpunks(a)toad.com mush will also allow filtering based on more or less whatever you want (e.g. To: fields). Mark -- Mark Henderson markh(a)wimsey.bc.ca

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POLI/TECH/SURVEY: Feds and computers.
by Alexander Chislenko 19 Mar '93

19 Mar '93

There were two interesting articles today in the Marketplace section of the Wall Street Journal. I advise you to read them, and will give only brief references here: 1. "White House lets you turn on your PC, tune into politics" - Some stuff on White House and its email addresses, email in general, etc. Some of it informative, some stupid, some babble. One remarkable piece: "... the backward White House computer system doesn't receive the electronic messages directly, and the mail isn't answered electronically. Instead, the e-mail messages are delivered to White House on disk, where they are printed out and answered by low-level workers through regular paper mail." Ain't that amazing?! 2. To the right from the big central material on the crucially important subject of bacon sales, there starts an article "Ruling gives privacy a high-tech edge" - about the Jackson Games BBS case. While it might not offer conceptual breaktrhoughs to anybody on this list, it is (IMO) a very informative and sympathetic material; it describes the history of the case, recent rulings, their implications, etc. It is very nice that this is offered to a large audience. - Well worth reading. ------------------------------------------------------------------------------ | Alexander Chislenko | sasha(a)cs.umb.edu | Cambridge, MA | (617) 864-3382 | ------------------------------------------------------------------------------

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Re: You Aren't [I'm Not]
by pmetzger＠shearson.com 19 Mar '93

19 Mar '93

> From: Theodore Ts'o <tytso(a)athena.mit.edu> > > Sorry; typo on my part. What I meant to say was "No, I am not arguing > that free speach is bad." Mr. Metzger was putting words in my mouth > when claimed that I was saying that. > > Anonymity and free speach are *NOT* the same thing. As I posited in an > earlier message, which no one has yet to comment on, those two concepts > are not the same thing. Yes they are, Ted. They are mathematically equivalent. If I can say anything, I can say it in code. If I can say anything, I can repeat what someone else said in code, possibly transforming it. Ta Da, remailers. To stop remailers, you will need to stop free speech. Please at least admit this much. It might be unpleasant, but in a society with no prior restraints on speech it is likely not possible to stop cryptographic systems to assure anonymity. Perry

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Re: Cypher: Subject naming proposal
by karn＠qualcomm.com 19 Mar '93

19 Mar '93

Several years ago I wrote a UNIX utility that splits my incoming mail (directly from the spool) into files based on the To: and Cc: fields. I can specify the various mailing lists to which I subscribe in the shell script, with all others going to a file named "other". This way I can give higher priority to the mail that names me specifically as a recipient, and put off the mailing lists for later. And I can use any conventional mailer (like Mail) to read the split files. Phil

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Tagging data to detect thieves
by Marc.Ringuette＠GS80.SP.CS.CMU.EDU 19 Mar '93

19 Mar '93

I've done some further thinking on the text tagging problem, spurred by a question on sci.crypt about tagging pictures (under the subject line "Permanent signatures for pictures"). Here's a summary. ---- Let's say Dow Jones wants to sell newswire subscriptions to individuals, but someone is anonymously forwarding their articles to a newsgroup. Can they succeed in tagging the text to detect the thief? The idea is to make some small twiddle to each subscriber's copy of the text, so that the stolen copy can be matched with some subscriber and their subscription cancelled. Short answer: the thieves win. At first, I thought the answer was the opposite. ---- There are two issues which must be addressed in order to show that the tagger wins: 1. The taggee must not be able to "smooth away" all of the tag bits. 2. The taggee must not be able to cross-correlate multiple copies of the data in question in order to produce a "clean" version. Regarding issue #1, the basic techique is to alter a few features of your data which are important enough that your opponent can't afford to randomize ALL such bits. In the case of text, small changes in word choice are a good candidate. Two criteria are: A. The changes must be "important" enough that the thief can't smooth them all away. B. The changes shouldn't be "important" enough that the newswire becomes worthless! The tagger has an advantage in this case, though. He can change, say, 1 in 1000 of these "important, non-smoothable-away" candidate bits. If the thief wants to cancel them out and only has a single copy of the picture, he must somehow canonicalize _all_ of the candidate tag bits, or some very large proportion of them. So if your tagging process does a little bit of "damage" to your data, like in the map-maker case of adding an extra small street here and there, then the opponent must either try to detect exactly where your damage is, or must make wholesale changes to the data (such as removing all small roads altogether). The thief, in trying to cover up your damage, must make a thousand times as much damage. Choose your damage level appropriately so that your level of damage isn't too much but the thief's is. ---- Issue #2, thieves cross-correlating between multiple copies of the data, is a bit more subtle. Here's the scenario: Dow Jones has 10,000 customers, 64 of whom are in a conspiracy to steal and re-sell the newswire. Dow Jones tries various tagging strategies, altering whitespace and word choice individually for each subscriber. The thieves try to cross-correlate between their copies of the text in order to "cancel out" the tags from the copy which they wish to re-sell. Can Dow Jones detect the thieves and cancel their subscriptions? In the discussion below, when Dow Jones "twiddles a bit" of their newswire, they do so by substituting a word's synonym at a chosen location, using a separate (possibly biased) coin flip for each subscriber. Here are the strategies I've considered. Dow Jones strategy: twiddle some bits with probability 0.5. If the thieves use majority vote, each thief will have a reasonably high correlation with the output bits. (In fact, the probability of a match will exceed 50% by approximately the chance of a tie vote among the thieves, which is about 0.8/sqrt(n) where n is the number of thieves. This computation is a bit hairy.) Thief countermeasure: reliably detect which bits are being twiddled (by cross-checking between, say, 64 different subscriptions) and flip a fair coin to determine the output. There's a chance of only 2 in 2^64 that the thieves fail to detect the twiddle. Dow Jones strategy: twiddle some bits with low probability (e.g. p=0.01). Reasonably often, the bit values will be the same for all thieves. If the thieves use the flip-a-coin strategy, we can determine which tag bits they've failed to detect, and identify them that way. Thief countermeasure: use a majority vote. Dow Jones strategy: hybrid of the two. Thief countermeasure: hybrid of the two. Flip a coin if the vote is fairly even, go with the majority if the vote is uneven. For example, get 64 subscriptions, go with the majority vote if fewer than 16 dissenters, flip a fair coin otherwise. This last strategy for the thieves is the one I can't beat. Theoretical help, anyone? -- Marc Ringuette (mnr(a)cs.cmu.edu)

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a steganographic test
by Eli Brandt 18 Mar '93

18 Mar '93

Taking the easy way out, I tried a steganographic encoding in a GIF by mapping down to 128 colors, duplicating them, and frobbing the low bits of the image. This worked surprisingly well. The resulting image showed little degradation, and was smaller than the original -- the information thrown out when mapping down to 128 was not fully replaced, as the "hidden" file did not fill the GIF. Rather than screw with GIF and Heckbert code for this throwaway, I did the {en,de}giffing and palette manipulation by hand with the PC program PICLAB. It supports scripts, which would automate the process, except for the palette duplication, which a sed script could do. The bit bashing code is appended, though it's pretty trivial stuff. Anyway, I ended up with the canonical Earth-seen-from-space, 320x200x8, with an embedded DOS-format text file chosen for verisimilitude. I can ship it by e-mail to anyone who wants it, though there's not really a whole lot you can *do* with the thing. ("Hey. Wow. There really is a file in the low bits.") PGP 2 key by finger or e-mail Eli ebrandt(a)jarthur.claremont.edu the guts of ensteg.c: /* * We smear the hidef stream MSB-first into the low bits of the picf stream. * This code is not optimal, but hey, it's short. */ int picbyte, hidebyte, mask=0; long count=0; while (EOF!=(picbyte=getc(picf))) { if (!mask) { mask = 0x80; if (EOF==(hidebyte=getc(hidef))) hidebyte=0; // pad with nulls } putc(picbyte&0xfe | ((hidebyte&mask)/mask), outf); mask/=2; } and of desteg.c: /* * Pull the picf bits out, and put them together, MSB-LSB order. */ int picbyte, hidebyte=0, bit=7; while (EOF!=(picbyte=getc(picf))) { if (bit<0) { putc(hidebyte, hidef); hidebyte=0; bit=7; } hidebyte |= (picbyte%2)<<bit--; } if (bit<0) putc(hidebyte, hidef); Caveats: no error checking. The pic file had better be eight times as large as the file to put in it. If the null-padding will cause problems, you should wrap the file with an archiver first. Sorry about that putc() line in ensteg.c; it was late.

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HASH: cryptanalysis of MD5? (fwd)
by root＠rmsdell.ftl.fl.us 18 Mar '93

18 Mar '93

Forwarded message: > Newsgroups: sci.crypt > From: schneier(a)chinet.chi.il.us (Bruce Schneier) > Subject: Successful Cryptanalysis of MD5 > Message-ID: <C42Gr3.M3w(a)chinet.chi.il.us> > Organization: Chinet - Public Access UNIX > Date: Thu, 18 Mar 1993 04:06:39 GMT > > This is from Bart Preneel's Ph.D. thesis, "Analysis and Design of > Cryptographic Hash Functions," Jan 1993, p. 191. It is about the > cryptanalysis of MD5: > > B. den Boer noted that an approximate relation exists between > any four consecutive additive constants. Moreover, together > with A. Bosselaers he developed an attack that produces > pseudo-collisions, more specifically they can construct two > chaining variables (that only differ in the most significant > bit of every word) and a single message block that yield the > same hashcode. The attack takes a few minutes on a PC. This > means that one of the design principles behind MD4 (and MD5), > namely to design a collision resistant function is not satisfied. > > I have not seen the actual paper yet, which will be presented at > Eurocrypt. Both PEM and PGP rely on MD5 for a secure one-way hash > function. This is troublesome, to say the least. > > Bruce > > ************************************************************************** > * Bruce Schneier > * Counterpane Systems For a good prime, call 391581 * 2^216193 - 1 > * schneier(a)chinet.chi.il.us > ************************************************************************** > > -- Yanek Martinson yanek(a)novavax.nova.edu

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White House
by Matthew J Miszewski 18 Mar '93

18 Mar '93

Cypherpunks, MCI announced a new email address for access to the White House. However, This time they make no pretense that it will be read electronicly. From what I could glean from RISKS (I was in quite a hurry), the messages will be sent through the regular USPS. This appears to be a way to increase profits for MCI and Internet messages may very well bounce. Anyway, I know that the cypherpunks are trying to access the handles of power in this country and gain some respect at the same time. I also watched the last thread about what form our communication should take. Well, here's another chance. 0005895485(a)mcimail.com - White House Matt mjmiski(a)macc.wisc.edu

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