December 2003 - cypherpunks-legacy

[noise] The economics of super-stars - partial cite
by Simon Spero 17 Dec '03

17 Dec '03

This came up at the bay area cyherpunks meeting - I haven't got the full citation, but the orignal paper was by Sherwin Rosen of the University of Chicago; it was published in 1981, under the title "The Economics of Superstars" - I think it might be in: TITLE: Studies in labor markets / edited by Sherwin Rosen. PUBLICATION: Chicago : University of Chicago Press, 1981. DESCRIPTION: ix, 395 p. ; 24 cm. SERIES: Conference report / Universities--National Bureau Committee for Economic Research ; no. 31 Simon (defun modexpt (x y n) "computes (x^y) mod n" (cond ((= y 0) 1) ((= y 1) (mod x n)) ((evenp y) (mod (expt (modexpt x (/ y 2) n) 2) n)) (t (mod (* x (modexpt x (1- y) n)) n))))

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How to make someone else lose ecash
by Ian Goldberg 17 Dec '03

17 Dec '03

I don't recall seeing this on cypherpunks or on ecash(a)digicash.com; it's being sent to both places, so set your replies appropriately. Dave and I were discussing the ecash protocols when we discovered what seems to be a way for Eve (a passive eavesdropper) to cause anyone to lose money. Note that she doesn't gain anything from it. Eve watches for any message that contains pcoins (a list of onl_coin). These messages are the Payment (from user to shop) and Deposit (from shop to mint). Neither of these are required to be encrypted. An onl_coin is the following: onl_coin = [ int keyversion ; low 5 bits are denomination MPI n ; coin number MPI sig ; encrypted coin signature ] sig is (f(n)^(1/h) XOR f(payment_hdr)), encrypted in the mint's public key. The reason sig is encrypted is so that the payment header can't be changed and so that Eve can't learn f(n)^(1/h). However, n is sitting there all nice and cleartext. Therefore: when Eve sees such a message, she uses the same value of n to withdraw a coin from her bank account, and then spends it (she could just pay it to herself). Eve does not gain or lose anything, but if she can deposit the coin before the original coin that she saw gets to the mint, the original coin will not clear. If Eve has the ability to drop or delay packets, she can accomplish this easily. The result is that whoever withdrew the coin originally has lost the use of that coin. Note that this is the same problem as if two users just happen to use the same value of n when they withdraw coins. We don't really care about that, since the probability is trivial. However, this attack lets Eve produce the same effect _on purpose_. How can we prevent this? Well, since a shop has no way of using the value n except for just sending it on to the mint, we lose nothing by encrypting it. Thus, an onl_coin should be: onl_coin = [ int keyversion ; low 5 bits are denomination Encrypt_with_mint_public_key( MPI n ; coin number MPI sig ; (f(n)^(1/h) XOR f(payment_hdr)) ) ] Note that it's not really necessary to have sig already encrypted if we're going to encrypt it again. Actually, I think an onl_coin should have an additional field (bankID) to the fields listed above, but that's another argument for another time. - Ian "Back from the North and ready to party!"

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Re: COMMUNITY CONNEXION REFUSES TO CENSOR INTERNET SERVICES
by Duncan Frissell 17 Dec '03

17 Dec '03

At 04:14 PM 1/14/96 +0000, attila wrote: > > an excellent statement, sameer. many of our population around the > world will voice these sentiments, but how many will care to implement > in the face of an onslaught by pressure groups, government, self- > serving news services, etc? Of the 7000+ ISPs on Earth, more than 1000. More than enough. DCF

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[Local] Portland Cypherpunks Meeting Update
by Alan Olsen 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- There have been no changes to the time and date of the Portland Cypherpunks meeting. For those of you who have not seen the past notices of the meeting, here are the details: Place: The Habit Internet Cafe 2633 S.E. 21st Av. Portland OR 97202 SE 21st @ Clinton (503) 235-5321 http://www.teleport.com/~habit/ Date: January 20th, 1995 Time: 5:23pm (Discordian time) Activities: There will be a general discussion of assorted topics including planned projects of the various participants, a PGP key signing, and general socializing, among other things. If you need instructions on how to get to the Habit, send mail to alano(a)teleport.com or habit(a)teleport.com and I will send you directions. It has been requested that cameras not be brought to the meeting as some who are planning on attending would like to avoid having their soul captured by the evil magic of the lens. If you are planning on participating in the key signing (and you do not have to if you do not want to), please follow these instructions: Send a copy of your public key (ascii armored) to alano(a)teleport.com. (This will also help me determine how many people are planning on attending.) I will compile all of the keys into a keyring which will be handed out on diskette. (Please tell me the format you want the disk in. Nothing too exotic, (like IBM mainframe formats and the like) please.) I can also e-mail the keyring to you as well. I will hand out a list of the fingerprints of the keys on the keyring. At the meeting we will verify key fingerprints. When you get home, you can then sign the keys at your leisure and mail them back to me. I will then send them to the key servers and the participants of the keysigning. ***PLEASE DO NOT BRING YOUR PRIVATE KEYRINGS TO THE MEETING*** For more information on keysignings, check out: http://world.std.com/~franl/pgp/how-to-organize-keysigning.html If you have any more questions, just send me e-mail at alano(a)teleport.com. My public key is: - -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.2 mQENAy9jYK0AAAEH/1nM2SOeaUJfF1iK+LlPEueZci3AIMDVDLGqjLStvwqKrD/g 8yKtw3oqrw3+bFsyW6EYAj1EFSRXO/9sFgbfQePOtyDoEHyx9jjROz+5zVmyAe4S KJwtNzmjBk6xfseR+0v7uKYcWQ2YYy4IL2d5zuUe+7HqxY+Mhr0jiViHFVvbIdXW 3Bnlob/8oprNsXl7MOqCAGMoL8WN2VIXJVU07Jm5XhEHIHVPtID5PjxCV9yT/XNV cJkSOi0/EYPG8EsCfwP8s8o1oVNya6mraDaIiAc/oPrwjb+XUrWiiELCBtInoy/8 wQYKq1GAmsnnCSk+2jTnNh7/WX195AI/e/fQJ5kABRG0H0FsYW4gT2xzZW4gPGFs YW5vQHRlbGVwb3J0LmNvbT6JAJUDBRAw3hjmZMnrupLu9OkBAYdFA/9wFA/VwaSH m46CADZNUaVuDPa6FJRIrI2cqZRxKS4Xo4mrYXfLlhDwWYRUPd65X2U32NAdO7WN TuvZL1lKNnq5Jd5WMxdzL3GEcONqIKPPWe+xbZtzaQxtKbuU1V9DlipZb+iL48Ca enhQKgYNnIiGtj5XxO/CLiSAbqju5z4pMokBFQMFEDBqUUXkAj9799AnmQEBvwQH /00LtGsFDi8Cpv3/hAyXdHDpfrzTo/Cr4UZkf6yeQjm75RyWLG2Dst10P//y52F5 Ixl/H2LDecnmYsYxZ9ij0Js1DfQqL1iu37+0O70z9I966DMizNeJ05nBNTHFOJu9 YXiHYSfLdr8OgS8rU78b+SsMdx1cufO0B5jMlW2wK9eBnNQ/V1gIl8X5dWvp5L6f nH0+g2eACPNs1TgFW9Z4Zh+cFMJPqIJ8x4LxQEqkC/174TzjM2KyDKJNMTBYeSCs apx76uAS8AlyNGgPC4jn0vOWsa++vPR/qddTLa+WZ/TEp4oYdxclgYzcR9szXn3d fE6Nn9ur2PFx7zWb5OL/GOCJAJUDBRAwagneGrGpUK3dPgUBAdMIA/9VjejKbiOe LmEcJP0yLx6xIVMzf0FcojsM4pF/rPQ2AbyNo2I8NR0XJTU8cq+8RntnYdk+GzEd l1F0pTg+vSE5mrYAFhqhjUTRmwFmyLl8DP6qeLZ1jrBbiFQzGa2ryJvFc101BLNo EH8Aw6rR0XpAGxdwAdTeizwDLxTxV8n/Eg== =NDqF - -----END PGP PUBLIC KEY BLOCK----- -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQEVAwUBMPitSOQCP3v30CeZAQF7Igf+JxGu1D3t33Xo9ME1w5bmQAYWIyVGCUGu OOVep+YcCxPK/xnEvul6BhyxMqAVXudw1u/U0kXvwJ366cWEts+AcTe7FdYBVt81 R/H9mJFCue9RvclyOPGL5th2fh94HtoslnqZ8Nu1CReMRjCU+kOrBsN4dZ9kMtxK fNKc8VHDQk2tYPcnhkeDvvg1CJhVQIE6Hn7IjOrkMnKn0xz7qKnsfhu+ECMGFfJH lC10iLS59BUztDtd+ye790lrEsk2Gp3OXrkBVR7ZE1QcehGUMOEspGJWq0bjsdW0 ftj4Nf+w+FVeYYCC+6XQSW7Dnvqs9tC1xV2LiSaCqdhS+KG1Iz2/+g== =K8VR -----END PGP SIGNATURE----- Alan Olsen -- alano(a)teleport.com -- Contract Web Design & Instruction `finger -l alano(a)teleport.com` for PGP 2.6.2 key http://www.teleport.com/~alano/ "Is the operating system half NT or half full?"

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Re: Good Riddance to Wiesenthal and His Nazis
by Alan Olsen 17 Dec '03

17 Dec '03

At 12:16 AM 1/11/96 -0800, you wrote: >At 6:26 PM 1/10/96, Adam Shostack wrote: >> The Wiesenthal center is very influential in Jewish circles. >>Attacking them directly would probably be a bad idea, and create bad >>associations for anonymity amongst Jews. (I'll come back to this.) > >I for one won't hesitate to criticize these Jew Nazis. This thread is near to the end as the "Nazi Card" has been played... It looks like "White Supremacists" are destined to become the "fifth horseman", thus preserving the "law of fives". I expect to see more uses of this horseman to attempt to reign in the internet under the yoke of Government control. There should be a story on one of the news tabloid shows any day now... OBNonSequiter: I was going through old mail and came upon a rant claiming that "the End of the Government was at hand!". It reminded me of some discussions here about a year ago where various on the anarchist side were declaring the "imminent death of the state" (GIF at 11). A quote came to mind... "The death of the state is not going to be like some old man dying in the corner. It will be like an old man in a crowded building having an epileptic seizure with lots of guns!" | Remember: Life is not always champagne. Sometimes it is REAL pain. | |"The moral PGP Diffie taught Zimmermann unites all| Disclaimer: | | mankind free in one-key-steganography-privacy!" | Ignore the man | |`finger -l alano(a)teleport.com` for PGP 2.6.2 key | behind the keyboard.| | http://www.teleport.com/~alano/ | alano(a)teleport.com |

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Buying Digital Postage Stamps Anonymously
by tcmay＠got.net 17 Dec '03

17 Dec '03

This came up in today's Bay Area Cypherpunks meeting (a very good meeting, by the way). It also has come up in a couple of the messages here, with mention made that the stamp seller may know who is using his remailer because he has records of who he sold the stamps (= numbers) to. There are several standard solutions: 1. Two-way anonymous communication, and two-way anonymous e-cash. ("Wrappers" and all that stuff, stuff I don't here us talking about much lately...) 2. "Stamp mixes," wherein users exchange stamps bought earlier. (This still depends on trust that the seller will not have kept copies of the stamps for his own use, thus wiping out the value of one's new stamps, or that he won't keep records. Anonymity techniques in the mix could help with some of these problems.) 3. Cash purchase with message pool posting. This last one I'll spend a moment describing, as it is very easy to understand, and is robust against a lot of attacks. Alice wishes to buy 100 remailer stamps, each worth 20 cents. She places a $20 U.S. banknote and a diskette containing a public key in an ordinary paper envelope and mails it from a random mailbox to Bob. She also includes a simple phrase to make it easier for her to later find the stamps, such as "Rosebud." Bob creates the digital stamps, encrypts the list of them with the public key provided, puts the name "Rosebud" on the file, and places it on his Web page which is visited by many people daily, or, for more security, posts it to a Usenet group devoted to such things (such as alt.anonymous.messages). Alice retrieves the digital stamps by either visiting Bob's Web site, with some small amount of identity leakage possible, or reads the messages in alt.anonymous.messages (with even less chance of leakage). Or, Alice could use a Web proxy to more securely visit the site. The net result is that Alice has $20 worth of digital stamps, Bob has a $20 bill and will honor the stamps he issued, and Bob doesn't know who he sold them to. This is how easily it could be done. Digital cash is not needed, at this granularity ($20 bills sent through the mail), and simple trust works. (We talk a lot about "reputations," and this is a concrete example. Protocols that "force" Bob to honor a digital stamp, instead of relying on his willingness to honor his promises, are vastly harder to design and use than are such simple, micro-trust transactions.) Different remailers would have different stamps, different rates, etc., and a remailer script (for a "premail"-like app?) could take the remailer hops planned, pull a stamp off the list of unused stamps, and put the number in a remailer-like header field, such as: :: Digital-Stamp: 5he20o#xL3p01SA29s The receiving remailer would decrypt the message with its private key, check the digital stamp field (as above, or in a real header format, whatever), and see if the stamp is in its list of "issued, but unused" stamps. And so on, in the obvious way. Seems straightforward to do. --Tim May We got computers, we're tapping phone lines, we know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay(a)got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^756839 - 1 | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."

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anonymizer.cs.cmu.edu
by ghio＠netcom.com 17 Dec '03

17 Dec '03

I tried this site http://anonymizer.cs.cmu.edu:8080/prog/snoop.pl using Mosaic 2.7b2 and was told: Your computer is a X11;Linux 1.2.13 i486. Your Internet browser is NCSA Mosaic. You just visited the Anonymizer Home Page. With Arena it gave me: Your Internet browser is Arena/0.96s libwww/. Lynx came up with even less: Your computer is a Unix box. Your Internet browser is Lynx. I did manage to completely confuse it with: > myriad:~> telnet anonymizer.cs.cmu.edu 8080 > Trying 128.2.199.14... > Connected to LCON.PC.CS.CMU.EDU. > Escape character is '^]'. > GET /prog/snoop.pl > <HTML><HEAD> > <TITLE>I CAN SEE YOU</TITLE> > </HEAD> > > <BODY BGCOLOR="78789F" > text="#FFFFFF" > vlink="#dbdb70" > link="#FFFF00" > alink="#1010ff" > > > > <center> > <img alt="Anonymizer logo" src="ftp://anonymizer.cs.cmu.edu/pub/I19"> > </center> > > <HR> > > Many people surf the web under the illusion that their actions are > private and anonymous. Unfortunately, it isn't so. Every time > you visit a site, you leave a calling card that reveals where > you're coming from, what kind of computer you have, and other > details. Most sites keep logs of all your visits. In many cases, > this logging may constitute a violation of your privacy. > > > > Here's a sampling of the kind of information that a site can > collect on you (please wait a moment): > > > > > > <BLOCKQUOTE> > > > <img src="/let/a.gif"><img src="/let/j.gif"><img src="/let/u.gif"><img src="/let/r.gif"><img src="/let/i.gif"><img src="/let/s.gif"><img src="/let/o.gif"><img src="/let/n.gif"> > > Your name is probably ajurison, and you can be reached at ajurison(a)netcom20.netcom.com. > > > Your Internet browser is [unknown browser]. This time it actually took a stab at the user name, and got it completely wrong, although the hostname (netcom20.netcom.com) was correct. I suspect it used finger and took a wild guess. The rest of the information is obvious from the User-Agent header, though I find it unusual that the new Mosaic reports the cpu/os type: User-Agent: NCSA_Mosaic/2.7b2 (X11;Linux 1.2.13 i486) libwww/2.12 modified Mosaic 2.4 reports only: User-Agent: NCSA Mosaic for the X Window System/2.4 (L10N-2.4.0) libwww/2.12 modified Lynx reports: User-Agent: Lynx/2.2 libwww/2.14 The statement "Your computer is a Unix box." seems to be just a likely guess, but it could be wrong, because there is a version of lynx for MSDOS. What suprises me is not the information this got, but what it *DIDN'T* get. It never managed to figure out my username, despite the fact that netcom runs identd, and all three web browsers give it my username when they opened the FTP connection. It only reported the hostname in one instance, and seems to be ignoring the info from the ftp session. This "snoop" script isn't getting half the information it could!

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Bignum support added to XLISP 2.1h
by pcw＠access.digex.net 17 Dec '03

17 Dec '03

Many cypherpunks might enjoy programming in XLISP 2.1h because the freely available implementation of LISP now offers support for BIGNUMS. That means it is quite easy to write cryptographic algorithms that use very large numbers without adding extra support. The downside is that the language is interpretted and thus much slower than something like C. It should also be possible to write RSA in a very short XLISP program. I don't know if you can do 4 lines, but it should be quite short. -Peter

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PRETTY GOOD PHONE PRIVACY, TOO
by James M. Cobb 17 Dec '03

17 Dec '03

Friends, 01 14 96 Edupage includes: PRETTY GOOD PHONE PRIVACY, TOO Now from the creator of PGP encryption software comes a new product for making your phone calls more private. Philip Zimmermann's PGPfone software scrambles phone calls made through a computer modem using a complex algorithm called Blowfish, which rearranges the digital version of your voice conversation and then decodes it at the other end. The result is an intelligible -- though not high-quality -- totally pri- vate conversation. The URL is: http://web.mit.edu/network/pgpfone (Popular Science Jan 96 p43) Cordially, Jim

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DEC's MICROCASH
by James M. Cobb 17 Dec '03

17 Dec '03

Friend, 01 14 96 Edupage includes: MICROCASH Digital Equipment filed a patent last August for a payment system called Millicent, which enables Web-site operators to charge as little as a tenth of a cent for each customer "hit." The system relies on middle-men --credit card companies or digital banks -- to handle the transactions, but its novelty lies in its cost-effective design geared toward tracking minuscule amounts of cash. To keep disk storage at a minimum, security measures providing privacy and a trail of signed re- ceipts are not included in the system, but proponents point out that would-be cyberthieves would have to crack a lot of trans- actions -- 10,000 at 0.1 cent each -- to make just $10. "There are easier ways to make 10 bucks," says Millicent's inventor. (Business Week 15 Jan 96 p90) Cordially, Jim

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