December 2003 - cypherpunks-legacy

Re: Still more on the Digicash protocol
by Mark Twain Ecash Support 17 Dec '03

17 Dec '03

At 06:01 PM 12/6/95 -0500, you wrote: >Hal has pointed out that payments & deposits with a wildcard in the >payment_hdr should NOT be sent in the clear, since they can be stolen >by any passive eavesdropper. Let us contemplate in which type of situation the payee will send such a wildcard coin. To pay a shop via TCP? No. The payment request comes in with the shop ID. The resulting payment won't be done with a wildcard coin. So when will the user pay with a wildcard coin? To make a payment to a party that is (pseudo-) anonymous to the payor. That is, if the payor sends the payment via anonymous remailer, in which case the messages should be encrypted anyway. [Why a remailed message should be encrypted is left as an exercise to the reader.] >Ian has pointed out the same problem with cancellations: the payer_code >should NOT be sent in the clear, since any passive eavesdropper can >grab this info and steal the corresponding payment. As mentioned before, this will be fixed. >Anyhow, the obvious solution is encryption. Our new observation is >that encrypting deposits & cancellations with the mint's public key >is not enough to solve the problem. [Argument in support of claim elided... I am not conviced.] >While I'm ranting, let me also remind you of a problem Ian discovered >earlier through reverse-engineering: the payment & deposit messages aren't >encrypted, [...] >With traffic analysis, if payers use the default TCP connection, all >this information about them can be compiled. If I target a payer, I'll >probably be able to record all his transactions (unless he's using >remailers or pipenet). If I sit outside a small business, I can compile >a dossier on its buying habits. One more time: this is only an issue if the payor is using a secure http connection. Otherwise, you can gather all that information with out without Ecash. The next release will use an already established SSL connection to transmit this information, should the payor request it. >Worse still, anonymity for the shop is worse with Digicash than with real >cash. If I pay you real cash on a secluded street, you're fairly anonymous. >If I pay you Digicash over the Internet, any passive eavesdropper could be >recording your identy and the whole transaction. Blech. This is raising an issue that has nothing to do with Ecash. The complaint is in fact about the lack of a gereral link encryption on the Internet. I agree that this is needed, but providing it really isn't Ecash's job. I am eagerly anticipating the general use of IPSEC. > (Yes, this means shops will need to have certificates if you want > to avoid a man-in-the-middle attack. So be it. Most online shops > will be using SSL, and thus have a certificate anyhow. You can safely > punt on the authentication between customer <-> shop if you're not > worried about active attacks.) That's why the next version will use existing SSL, should the user so desire. >* add a big warning to the documentation: users should not use wildcards > in payments (unless they know the dangers & are encrypting with e.g. PGP). Will do. >* continue specifying the protocol at a deeper level, like you promised > (and throw in source for security-critical modules too, eh? :-) Writing all this down takes time. DigiCash may hire a tech writer soon. That should improve communications between all parties. --Lucky Green --Mark Twain Bank Ecash Support Ecash. The secure Internet payment system that protects your privacy. <http://www.marktwain.com/ecash.html>

2 1

More FUD from First Virtual
by cman＠communities.com 17 Dec '03

17 Dec '03

It is important to remember that Nat Borenstein is a principal in a company that very much does not want to see anonymous e-cash succeed. Their extremely backwards technology cannot compete in the long term with cryptography-based methods, and therefore they are compelled to run around the country and on the Internet, bad- mouthing cryptography and anonymity at every turn, while pointing to some charity work for Phil Z. as a fig leaf to cover their actions in this regard (sort of like Exxon building an artificial reef and claiming to be friends of the environment.) I have, on several occasions, refuted his "infinite liability" rant, but it keeps on resurfacing. A few months ago, I wrote a short tech note on why this claim doesn't hold water. I thought I might stretch it into something longer, but other things have more urgently grabbed my attention. It's available at: http://www.communities.com/foo/noninf.txt Also, I haven't had time to confirm it, but based on conversations with and hints from Digicash people online, I'm pretty sure they are doing something similar to this (possibly better) that they are hoping to patent. --doug

2 1

@v@ XXX
by nobody＠REPLAY.COM 17 Dec '03

17 Dec '03

Wall Street Journal, 8 Dec 1995 On-Line Society Angered by Plan to Curb Content By Jared Sandberg The latest move in Congress to curb "indecent" material on the Internet triggered outrage and scorn in cyberspace, as on-line users decried it as censorship and plotted ways to overturn it. "Welcome to the age of electronic book burning," said Craig Johnson, a consultant who worries that the term "indecent" could be applied to literary works, publichealth and medical exchanges, and serious discussion of AIDS and sexual behavior. "It's not only ridiculous - it's unfair, un-American and unconstitutional," said Eileen Kent, vice president of new media at Playboy Enterprises Inc. She finds it "incomprehensible" that the on-line version of Playboy could be deemed illegal while the printed magazine isn't. "Are they going to send me to jail and fine me a hundred grand because I put a Playmate on the Net?" she asked. If so, "then I'm quitting." House conferees hammering out a sweeping telecommunciations bill voted 17-16 on Wednesday to make it illegal for anyone to knowingly display indecent material that can be viewed by a minor, punishable by a $100,000 fine and up to two years in prison. Yesterday, critics tried to counter punch. The American Civil Liberties Union is preparing a court challenge on First Amendment grounds. The Center for Democracy and Technology, a cyberspace civil-liberties group, vows to do the same. On-line services drafted a letter of protest to House Speaker Newt Gingrich, who has opposed earlier attempts to impose restrictions on Internet fare. On-line advocates also are pushing for a new vote by the House conferees to define just what "indecency" means. They are hoping the 17-16 balance of the first vote is tenuous enough to allow them to ease the restrictions in defining the terms. Backed by the hectic lobbying efforts, Rep. Rick White of Washington state, who favors a less-restrictive approach, and allies have begun laboring to devise a limited definition of indecency that would be acceptable to civil libertarians and smut-fighters alike. Without a clearer, limited definition, the "indecency" standard faces the almost certain prospect of being struck down by the courts as unconstitutional, the White forces contend. On-line experts, moreover, argue the latest measure could create big problems and unintended consequences. If one 16- year-old zaps lewd fare to another, could the sender be imprisoned? If an adult makes a racy observation on an electronic bulletin board and a minor tracks it down and reads it, should the adult be punished? Last week, America Online Inc., in an effort to strike vulgarity from members' personal on-line "profiles," decided to strike all uses of the word "breast" - and thereby erased the biographies of scores of women who had breast cancer. AOL "responded to the climate of fear created by Congress," Mike Godwin, legal counsel for the Electronic Frontier Foundation. An AOL spokeswoman said the deletions were "a mistake on our part." Robert L. Smith, executive director of the Interactive Services Association, said such snafus could occur more and more as Internet access providers fret about whether their so-called content might be deemed indecent. "It's going to cause confusion, industry uncertainty and years of litigation, which will result in Congress not solving the problems they wanted to solve," Mr. Smith said. The crackdown effort, moreover, may be fruitless in a global computer network that reaches more than 150 countries. "Those American laws don't apply to me," said Patrick Groeneveld, a professor at Delft University in the Netherlands. Mr. Groeneveld, who once ran a popular Internet archive that included pornographic material, said Congress's efforts amount to U.S. "imperialism." "I didn't vote for America's congressmen," he said. "Legislators and some consumers don't understand the Internet," said Jerry Berman, executive director of the Center for Democracy and Technology. "So, it becomes an easy target for political posturing." -- Albert R. Karr contributed to this article.

1 0

Re: Still more on the Digicash protocol
by Rev. Mark Grant 17 Dec '03

17 Dec '03

On Thu, 7 Dec 1995, David A Wagner wrote: >Tough!? It's trivial for an active attacker, in the stream cipher case. >He just xors some bits: no clever cryptanalysis needed. (Or did you mean >it's tough to mount an active attack? I agree: that requires significant >knowledge or motivation.) Exactly.. once you have an active attack set up, it's trivial, but setting that up is quite hard. Mark

1 0

Java musings
by fc＠all.net 17 Dec '03

17 Dec '03

Excellent musings. I just wanted to add something here. There is a fundamental issue with Java, and that is control: People in charge of organizations are responsible for what goes on within them. Without proper controls, it's impossible to carry out that responsibility. The people who want us to use Java are asking us to give up control over the programs run by our computers. They tell us to trust them because they say they have come up with a nearly fool-proof system for doing this safely. - They don't claim it's really secure, they only say it is harder to abuse than a C++ program. But nobody in their right mind would make it organizational policy to allow users to load and run C++ programs from over the Internet at the push of a button, and the removal of the particular things removed by Java are not adequate to justify this increased trust. - They won't back up their claims of security by assuming liability for resulting damages. Their liability disclaimers tell us they think their security is worth exactly nothing. They are asking us to bet control of our IT on a product that they take no responsibility for. - They don't even provide us with the ability to control their product in the way we control other purchased software we place into our environments. The inability to restrict which programs from which sources are run on our machines is a fundamental element of control. - Their product has been proven to be insecure in the past. Several examples of its insecurities have been demonstrated, and many more have been pointed out. There is essentially no counter point made by the Java supporters against these known defects. It seems to me that the loss of control resulting from the widespread introduction of Java would make it unacceptable to business. The use of Java as it exists today violates the policies of many businesses, and if their policies are ignored or changed to permit this to happen, it weakens the overall control structure of the organization. -> See: Info-Sec Heaven at URL http://all.net/ Management Analytics - 216-686-0090 - PO Box 1480, Hudson, OH 44236

2 1

Re: (Fwd) General release of Open Encryptor interface for PGP
by Tim Cook 17 Dec '03

17 Dec '03

Thanks Jeff, but aimnet.com is not an anonymous server. It dropped me as an unknown user. Thanks Tim Cook, Mindsource(tm) Librarian. "The World is a Database - Mindsource is the Search Engine." ______________________________________________________________ M I N D S O U R C E (TM) I N F O R M A T I O N N E T W O R K Send a blank Email to:mindsource@memo.net for full information Visit our W3 Site http://www.ultimate.org/mindsource/main.html D E S T I N E D FOR G L O B A L D I S T R I B U T I O N! Concept:"The Greatest Untapped Resource is Human Resource(TM)" Mindsource is a Reg. Trademark Copyright(c)1995 by Mindsource

1 0

Python Cryptography Toolkit v1.0.0
by Andrew Kuchling 17 Dec '03

17 Dec '03

I've just uploaded version 1.0.0 of the Python Cryptography Toolkit, a collection of cryptographic routines for the Python programming language. It's at ftp://ftp.cwi.nl/pub/pct/pycrypt100.tgz. All my code is public domain; some of the algorithm implementations are GPLed. The Toolkit now contains various cryptographic algorithms such as DES, IDEA, MD5, etc. I will fix bugs in the software, and may add or remove the odd module if some startling new research result comes out, but things should be pretty stable from now on. The algorithms available are: Hash functions: Haval, MD2, MD4, MD5, SHA. Private-key encryption: Blowfish, DES, DES3 (Triple DES), Diamond, IDEA, Alleged RC4, 32-bit RC5, REDOC III. Public-key: Digital Signature Standard, ElGamal, RSA. (There's a non-functional ESIGN module included, too; I'll finish it for a subsequent release.) Python is an interpreted scripting language; see http://www.python.org for more information, the source code, and binaries. It includes arbitrary-sized integers, so the public-key algorithms are implemented in pure Python; this entails a speed penalty, but makes the code more valuable for educational purposes. A sample usage of a hash algorithm (MD5) is: >>> import md5 >>> hash=md5.new() >>> hash.update(message) >>> hash.digest() '\235\361\034\357\217MX\2246\226\367\366Ebx\326' A sample use of an encryption algorithm (IDEA, in this case) is: >>> import idea >>> obj=idea.new('This is a key456', idea.ECB) >>> message="The answer is no" >>> ciphertext=obj.encrypt(message) >>> ciphertext '\2325$\343=)d\341^\025<\344\013\204 T' >>> obj.decrypt(ciphertext) 'The answer is no' Questions, comments, or suggestions are welcomed at the address below. Andrew Kuchling andrewk(a)cst.ca

2 2

Re: Geodesic Payment Systems?
by Duncan Frissell 17 Dec '03

17 Dec '03

At 04:40 PM 12/7/95 -0500, Nathaniel Borenstein wrote: >None at all, if you can find an underwriter who is comfortable with the >fact that his investigative options will be limited in the case of >suspiciously large or suspiciously frequent "cash out" events from a >given customer. Apparently Mark Twain Bank finds that risk acceptable. >I'm sure the larger banks will be watching quite closely. I seem to remember from my favorite Law School class -- Commercial Paper -- that banks weren't liable if they paid out an account from cleared funds under the terms of the account. A bank is responsible for payments made on a forged drawer's signature and anyone who accepts an instrument from a forged endorser eats the loss. But online clearing with digital signatures makes it hard to forge the drawer's signature and digital cash doesn't have the sort of endorsement system used on paper checks. DCF

2 1

Escrow expectations
by Adam Shostack 17 Dec '03

17 Dec '03

If there is no expectation of privacy when a key is escrowed with Bob, or my companies attorneys, then would there be any expectation of privacy under Clipper? Perhaps this is a powerful argument we should expect to have used against us... "Your honor, we argue that in escrowing his keys with the US government, the defendant should have known his communications could be listened to, and thus has no expectation of privacy." Adam -- "It is seldom that liberty of any kind is lost all at once." -Hume

3 2

PGP Interoperability?
by marina kats 17 Dec '03

17 Dec '03

Can anyone out there vouch for the interoperability of PGP 2.6 ui with versions of PGP available in USA from MIT & Viacrypt. What about the legal issue ? Is it legal for a US citizen to encrypt or check signatures with a 2.6ui public key ? Would sending a public key out of the US be reagarded as export by ITAR? Thanks Geoff Klein.

2 1