December 2003 - cypherpunks-legacy

RE: Mixmaster status
by loki＠obscura.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I apologize for being so terse in my first message. This is not a red herring. The organization that has approached me is very pro-privacy and anonymity. I see nothing but good coming from this venture. I will be very active in the development of the commercial version of Mixmaster. Let me be crystal clear. 1) I will not support any version of Mixmaster that is weakened. 2) All future clients will be able to generate the current message format. 3) All future servers will be able to read the current message format. 4) There will always be a free version of the client with source code. While I have not discussed it, I can not imagine that there would not also be a free version of the server code (with source). Without remailers what is the point of the client software? At 8:45 PM 9/14/95, ROBO Mixmaster Remailer wrote: >Flame Remailer <remailer(a)flame.alias.net> wrote: > >> Subject: Mixmaster status >> >> There has been an offer to purchase and commercially develop Mixmaster. >> This will hasten the development of Mixmaster for other platforms (e.g. >> Dos, Windows Macintosh), and bring significant improvements to the >> interface, but I will not compromise on the level of security provided by >> Mixmaster. Free client software will continue to be available. >> >> This could be the big breakthrough for remailers, finally thrusting them >> out of the hobbyist's closet into the corporate world. >> >> I wonder. Where is the commercial market for remailers? Who has an >> application for them except hobbyinst? Why would there be a commercial >> incentive to run a mixmaster server, or even a client? >> >> Could this "offer" be a red herring? > >I wondered the same thing myself. It would certainly be a more >cost-effective way for the NSA to compromise Mixmaster technology >than by brute force. > >Consider this scenario ... Mixmaster get's bought by the Acme >Crypto Company of Ft. Meade, MD. They "improve" it, and offer a new >version. It's even FREE (for non-commerical use)! But their >"improvements" make it incompatible with previous versions, and so >you have to upgrade. The new "commercial" version comes with no >SOURCE CODE, of course... -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQEVAwUBMFkzR/Pzr81BVjMVAQH6hAf+O+QdTEzNjUh0FYlJEnCakNws4MxPrOt4 miMPaz/aWDOReGb62UPZAEMNXP+hjgy0kTjW4xReTTBAPgtcsInr1Cct6MPr3O/r PGMGmE9z2Fkv3/k7MDG1NiptT2/RwVtmDikIJEQuH5j8ijir28Vvrk9Vs685Qc3j bFz5Q8uRLd57Uk51tQwIiBM6CJ4suQ3WFN++QNTHM9E47J9W8yFBux6ePWPlZOK8 8BnKkhY/auPm85X3MVZhL3y7F6zbFuqPpZrsKpwOOkme8o4l71t2xyhGcZHHxiB7 JLF2As9pNXsKWpYiPZEHTV9hsgxQTHortdhq25DeGyoxhZSrZByP/w== =+O16 -----END PGP SIGNATURE----- ---------------------------------------------------------- Lance Cottrell loki(a)obscura.com PGP 2.6 key available by finger or server. Mixmaster, the next generation remailer, is now available! http://obscura.com/~loki/Welcome.html or FTP to obscura.com "Love is a snowmobile racing across the tundra. Suddenly it flips over, pinning you underneath. At night the ice weasels come." --Nietzsche ----------------------------------------------------------

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Re: Explaining Zero Knowledge to your children
by Karl L. Barrus 17 Dec '03

17 Dec '03

At 08:18 PM 9/14/95 +0200, you wrote: >There is a paper about explaining Zero Knowledge methods in simple >words. It's titled "Explainig Zero Knowledge Authentication to your >children" or something similar. I think you are refering to Quisquater's (sp?) explanation, which is in terms of Ali Baba and a magic cave. A functionally similar explanation is in Schneier's Applied Crypto, pp. 85-86. -- Karl L. Barrus <klbarrus(a)infocom.net>

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Washington D.C. Cyperhpunks Meeting Cybercast
by Thomas Grant Edwards 17 Dec '03

17 Dec '03

Catch the WashDC Cypherpunks meeting cybercast on CU-SeeMe tommorow, saturday Sept. 16 starting at 3:00 PM on the www.digex.net (205.197.247.33) reflector. CU-SeeMe software is videconferencing for PCs and Macs and can be found at ftp.gated.cornell.edu -Thomas

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Re: your mail Re: on anonymity, identity, reputation, and spoofing
by nobody＠alumni.cco.caltech.edu 17 Dec '03

17 Dec '03

I do sympathize with L. Detweiler's concern about multiple identities. Human nature being what it is, if a series of posts appears quickly taking one view, people who disagree may think, well, I guess I'm in the minority on this, I won't make a stink about it. That's just part of the herd instinct, which, IMO, we all share. The lesson is that it is even more important on the net not to be afraid to take unpopular stands. You may find that there are more people who agree with you than you thought. In particular, although I think Detweiler's posts could be tightened up considerably, and I don't agree with his solutions in detail, I can understand his paranoia, having shared it from time to time. There are some possible technological solutions to some of the issues raised. Chaum, in his 1985 CACM paper, describes how "credentials" can be exchanged among various pseudonyms a person may have. A credential can basically be any statement by a 3rd party about a person. It could be a statement by a college that he had a certain degree. It could be a statement by a government that he had a driver's license. It could be a statement by a business that he was an agent for that business. The credential would be given to the person, then Chaum shows how it could be re-blinded and shown under other pseudonyms. The credential can be verified, but it can't be linked to the True Name or other pseudonyms of the holder. We could think about using something like this for reputations. Take Nick's question about how a new pseudonym could get through the filters. Maybe the person posts under his real name for a while, then some respected person is willing to give him a "valued poster" credential. He can re-blind this credential and submit it with posts he starts to make under his pseudonym. People will know that the pseudonymous poster is at least potentially capable of making sense, and give his words some weight. But there will be no connection to his True Name. (Of course, this could lead occasionally to a Dr. Jekyll who makes sensible and weighty posts under his own name, while under his Mr. Hyde pseudonym he rants and raves. But hopefully this would not happen too often.) Other credentials could be related to some of the other points Detweiler raised, such as list membership > some number of months. The point would be that these credentials are voluntary, used to get past people's filters, and that they retain poster anonymity while giving readers useful information about the poster. It's ironic that L. Detweiler, who has played a major part in spreading awareness of Cypherpunks technology through his widely read Privacy and Anonymity FAQ, is suggesting that people should be limited in their use of this technology. Still, the concerns he raises are going to be shared by many people, and we should try to be ready with technological solutions that are consistent with privacy protection. Hal Finney hfinney(a)shell.portal.com

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Re: Why ecash is traceable
by loki＠obscura.com 17 Dec '03

17 Dec '03

At 9:46 AM 9/15/95, Timothy C. May wrote: >At 8:47 AM 9/15/95, Donald M. Kitchen wrote: >>-----BEGIN PGP SIGNED MESSAGE----- >> >>Excellent discussion on the subject, actually. However, your idea of >>the "first person to the bank" maintaining anonymity via remailer block >>is flawed. First of all, if a collusion with the bank is being taken into >>account, presumably sufficient enough resources are involved that someone >>may try and track the reply block. Mixmaster (as your messages mentioned >>by name) would be necessary to eliminate the chance of tracking the block >>through combinations of replay attacks etc. (Which reminds me, has anyone > >Just to clarify a minor point, I mentioned "mixes," not Mixmaster. I have >nothing against Mixmaster, but "mix" is the term Chaum invented for what we >later started to call a "remailer." > >--Tim May > Indeed Chaum's phrase "digital mix" was the inspiration for the name Mixmaster. -Lance ---------------------------------------------------------- Lance Cottrell loki(a)obscura.com PGP 2.6 key available by finger or server. Mixmaster, the next generation remailer, is now available! http://obscura.com/~loki/Welcome.html or FTP to obscura.com "Love is a snowmobile racing across the tundra. Suddenly it flips over, pinning you underneath. At night the ice weasels come." --Nietzsche ----------------------------------------------------------

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Why ecash is traceable
by Hal 17 Dec '03

17 Dec '03

There has been considerable discussion on sci.crypt and on the cypherpunks list about the fact that currently proposed digital cash is "traceable", or to put it another way, that there is no payee anonymity. This is an annoying asymmetry, where the payor is protected more than the payee. But there is a fundamental reason for this, which I want to explain here. It is not just perversity on the part of digital cash designers. The problem is that there is a conflict between the desire for payee anonymity and the need to prevent double spending. And preventing double spending is far more important, since without that the cash would be worthless. Here is how the conflict occurs. Suppose Alice has a piece of digital cash which she wants to spend with Bob. She goes through some protocol and transfers data to him. Bob, then or later, sends some resulting data to the bank and gets his account credited. Now if Alice spent that same coin with Charlie, we need to have the bank find it out. When Charlie deposits his data with the bank, and the bank compares that with what Bob sent in, there must be a red flag that goes up. The fundamental requirement of preventing double spending implies that Bob's and Charlie's data, when sent to the bank, has some correlation which will identify the fact that they both come from the same coin. It doesn't matter exactly what the form of this data is, or how it has been blinded and stirred, but if double spending is to be detected there must be a correlation which the bank can see. But this correlation is what makes the coin traceable. Suppose Alice is paying a coin to Bob via an anonymous network, and she and the bank are going to try to figure out who he really is. She goes through the payment transaction, and Bob sends his resulting data to the bank. Before doing so, though, Alice simulates a payment of the same coin to Charlie. Charlie doesn't actually have to be involved, Alice can just go through what she would have done if she had spent the coin elsewhere. The result of this simulated payment has been shared with the bank. Now, when Bob deposits his data, the bank compares it with the data Alice sent, the result of her simulated spending of the same coin. By the argument presented above, Bob's deposit will be flagged. It will correlate with the data Alice sent in since this will be the equivalent of a double-spending. So when Bob makes the deposit he can be linked to the specific coin payment which Alice made, and his anonymity is lost. It would seem that any system which is capable of detecting double- spending just from the information which the payees send in to the bank would be vulnerable to this. Systems which use tamper-proof observer chips to prevent double spending beforehand can avoid it, but of course if someone breaks an observer the whole cash system might crash. In general it does not look like payee anonymity is possible without giving up other very important features. Hal Finney hfinney(a)shell.portal.com

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Re: Why ecash is traceable
by Donald M. Kitchen 17 Dec '03

17 Dec '03

Re: ecash being non-tracable if anon accounts are allowed... And if not, a market will probably develop to launder ecash. Don

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Re: DD, pedaphiles, and Terrorists, oh my
by shamrock＠netcom.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- In article <9509141640.AA30602(a)zorch.w3.org>, hallam(a)w3.org wrote: >We never used to see kiddie porn on the internet. The net would go balistic if a >picture of a teen age nude was posted. Recently there has been a flood of hard >core paedophile material. There has always been nude teens on the net. The kind of pictures the most casual observer can take at any Mediteranian beach at any given day in the Summer. There is no real kiddy porn readily available on the net. I looked long and hard. Its a red herring. ANYBODY on this list seen some real kiddy porn on the net? I am talking intercourse, etc., not scans of six year olds from the Sears catalog, or naked boys building sandcastles on the beach. - -- - -- Lucky Green <mailto:shamrock@netcom.com> PGP encrypted mail preferred. - --- [This message has been signed by an auto-signing service. A valid signature means only that it has been received at the address corresponding to the signature and forwarded.] -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Gratis auto-signing service iQBFAwUBMFjDkioZzwIn1bdtAQEB0gF+M67Ih6WLAl8J9bxPZOBmyjxKsxUczpqv th5x7ZuILyuf/+bFTtcLKwbOnzZkIfpJ =pjLL -----END PGP SIGNATURE-----

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PGP BUG/FEATURE: multi-platform keys
by nobody＠alumni.cco.caltech.edu 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Recently I have received two keys that were unusable without modification (from wonderer and Sameer) because they were not prepared using canonical text. I had to replace all the carriage returns by hand (this is the workaround for mac users who receive PC keys). Why is non-canonical text even an option in pgp? Who would use it except by mistake? As long as I'm at it, here are some more macPGP2.3 bugs, for those who care. Trying to decrypt a message signed by a key I don't have causes a serious crash requiring reboot. Trying to select cancel in a signature dialogue just raises the same dialogue box instead of cancelling. I'm running on a powerbook 145 under system 7.0.1. Eternal!Optimist(a)anon.penet.fi (copyright 1993, Eternal Optimist [Ha Ha Ha]) 0) 0) =:()]-< <na26436(a)anon.penet.fi> -----BEGIN PGP SIGNATURE----- Version: 2.3 iQCVAgUBLNe7R4jvfLxJbYYtAQFFHQP7BCqn1JKaI09wBrWnjOF73CPz7GetaC/y XL8zqhmzDdrGdLbWB/vBDgXW7z+2EJHazbvqaUhq1GQw8bq+opC2fe4mXcw2x3Y+ wliLy1CWDtfl24L8ah//nLQMtttfG4kXjiB8JqUnS7US+W3vvH3AXxi+wZb5W2qi 7gPXMErUCUA= =Ew/6 -----END PGP SIGNATURE-----

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Re: Digital Fingerprinting
by James Caldwell 17 Dec '03

17 Dec '03

On 12 Sep 95 at 11:27, Andrew Loewenstern wrote: > Such technology would be very useful in business, especially the > high-tech industry. Think of how many non-disclosure agreements > are signed every day relating to new products developed for the > software industry alone. Many companies are very paranoid and > already 'fingerprint' information by using unique code-names for > projects, for instance. i.e. the spec sheet on their new GAK > crypto product they give to Alice may be code-named 'project foobar' > but the one they give to Bob may be code-named 'project burris'... > Then, when the information leaks out they check which person they > gave the document with that code-name and they know who to sue (or > at least not give any more trade-secrets to). It's very simplistic > but it has been know to work in the past. > > Most of the real technology for doing this is much better, of > course... However, what stops you from printing out a > fingerprinted document and scanning it back in, for instance? Well, there is selective wording, mispellings, punctuation and formatting. These can be corrected easily if allowed to be transported as a text or common file type. Another way is to place the document in a PItA proprietary graphical format for transport and viewing only, stego identifier imbedded if you chose * , so that every portion of the document has some indentifier imbedded in it. Many obvious and many devious. Electronic drawings with a harmless and useless circuit(s) added on , software with do nothing code (by design!:) ). Difficult and time consuming to do, but for megabuck items, no prob. Automated for an additional fee of course. Start a service industry for such, make money, pay me back by running a fast, reliable remailer. Idea is to make the thief go to some major effort and if the scanning option is used to make the deletions as obvious and telling as the former identifier. > andrew note* Makes a neat way of putting copyright & source information in picture and sound files, somewhat useless but every trip up helps.

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