April 1993 - cypherpunks-legacy

FWEE! Re: alt.whistleblowers
by wcs＠anchor.ho.att.com 14 Apr '93

14 Apr '93

> Kick it around on alt.config >> Just do it .... The problem is that alt.whistleblowers is technically more complex than just creating an alt.group and having one anon.poster site - we need to resolve issues of secure mail standards (e.g. should the system use RIPEM or just PGP, are there any non-US sites with RIPEM so that non-US anon.poster sites can use it, should there be multiple anon.sites and should they do remailing between them, etc.) Otherwise we may end up with a single point of failure, and if it's any good, it will at least get its mail watched, if it doesn't get raided - traffic analysis is important here. Are we only going to use anon.posting sites, or are forged postings also going to be an acceptable technique? Do we at least need to publish a guide to forging mail headers so your mail to the anon.poster can appear to come from kremvax or whitehouse.com? Let's try to get a good idea of what we want to do before dropping it into alt.config. Bill Stewart -- This isn't the 8th Dimension, we're somewhere over New Jersey

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alt.whistleblowers
by Clark Reynard 14 Apr '93

14 Apr '93

I suggest that as a first step in the process of making alt.whistleblowers a reality, that we kick around the idea for a while, either here or on alt.config. If I receive a positive response, I will post the control message myself. Three possible choices of action: 1) Kick it around on alt.config. 2) Kick it around on news.groups, etc. 3) Kick it around here. 4) Don't even bother kicking it around; just create the group, and hell with anyone who doesn't like it. So, what's the general consensus on the best course of action? And, yes, I know that was four, and not three possible choices; it's probably really eight or ten. ---- Robert W. Clark rclark(a)nyx.cs.du.edu PGP signature available by mail or finger

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Re: Encrypted Cordless phones
by George A. Gleason 14 Apr '93

14 Apr '93

And also.... Radio Shack just entered the market with a cordless which uses frequency inversion. That's analog... Probably can be broken in less than a minute, even by amateurs who know how to solder. About 1986 or so, a certain state agency ordered some expensive walkie-talkies which were supposed to be secure against protesters with scanners. Guess what? Analog frequency inversion. And in fact, with a little practice, you can listen to inverted speech directly and make sense of it.

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REMAIL: Positive Reputations Now!
by Hal 14 Apr '93

14 Apr '93

-----BEGIN PGP SIGNED MESSAGE----- There's been a lot of talk on news.admin.policy about ways of handling abusive or illegal anonymous posts. One proposal is to restrict posts from certain people, but this will fail if multiple remailers allowing chaining become available. I had an idea for another way of filtering anonymous posts which might be achievable with current news software. It would require some work by the remailer operators, though. We have talked here about positive reputations as a filtering method. A positive reputation would basically be a recommendation by some respected person that a particular poster is worth listening to. If posts could be marked with such recommendations, people could set up their news software to filter out non-recommended anonymous posts. This would be a way of distinguishing between those who want to post anonymously just for privacy, and those who want to harrass or abuse others. Current news software doesn't provide for such reputations. But there were suggestions being made at one time for a standard way of marking anonymous posts. One idea was to give them a unique identifier in the "Distribution" field of "anon". I gather that this would require a little modification of major news distribution sites to honor this distribution but from what I understand the changes needed are not major. My idea is to implement positive reputations at the source which is in the best position to provide them: the remailer operator. Applying the distribution idea, posts which were from people on a "good guys list" would be posted from the remailer with a specific distribution that identifies them as such. Anonymous posts from people not on the list would get a different identification. In order to verify that posts were really from who they claimed, they would have to be PGP (or RIPEM or PEM) signed. The list would actually be a list of keys rather than a list of user ID's. People would get on the list by asking the remailer operator, perhaps by pointing to some of their posts which were responsible. People would be removed from the list at the remailer operator's discretion, presumably when they posted objectionable messages. The advantage of this system is that it introduces, in a limited way, the idea of positive reputations. It fits into the current killfile system so that people easily offended can avoid seeing most offensive anonymous posts. It encourages the use of encryption software on the part of people who want to post anonymously and get a good reputation. And the only difficult software requirements are in the remailing/posting software; everybody else just runs the current SW. Now, since I don't run a remailing/posting service, I am in the rather embarrassing position of offering a "solution" which requires somebody else to do the work. I would be very willing to help with the software requirements for recognizing incoming PGP signed messages and looking up keys in a database. The actual maintenance of the good posters list would take some time and energy on the part of the operator. But perhaps this would not be that much more than the other activities involved. And it would have the advantage that it would point out a new direction for the net, towards a system where privacy and responsibility can coexist. Hal Finney 74076.1041(a)compuserve.com -----BEGIN PGP SIGNATURE----- Version: 2.2 iQCVAgUBK8uFMqgTA69YIUw3AQFqswQAhx/GN/qg4Jx6Ggqh8Rmt6Lta1iN82dOQ gAAkEwcgJsMuvEjtcgRFkHxxW6uCF/8m2kLU3HUA8lnT94BR5TJc/0K5xH05gKhH NvU+74sCxIV68ef+0pz1X9TzC1E7tUxAhJKPQ80li1QFsBw5yATzuh1UHeDIk/5O 7yyVS8AGQFc= =RyI6 -----END PGP SIGNATURE-----

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Encrypted Cordless phones
by Sandy 14 Apr '93

14 Apr '93

_________________________________________________________________ FROM THE VIRTUAL DESK OF SANDY SANDFORT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ At the Bay Area Cypherpunks meeting, I mentioned two cordless telephones that encrypt between the handset and the base unit. Here is some information about them. VTech Tropez 900DX Transmits signal digitally between handset and base unit on one of 20 channels in the 900 MHz band. Automatically selects one of over 65,000 digital security codes each time handset is returned to the base unit. Range is up to 800 meters; with up to 4.5 hours of continuous talk time. Suggested retail cost is $349.95. For more information: Steve Johnson, (503) 643-8981. PhoneMate 2910 Transmits signal digitally between handset and base unit on one of 10 channels in the 900 MHz band. Automatically selects one of over 1,000 digital security codes each time handset is returned to the base unit. Range is up to probably about the same as the VTech. No figures are given for talk time. Suggested retail price is $219.95. For more information: Suzanne Nastaskin, (310) 314-6649. Both phones have all the usual advanced features like auto-redial and such. Neither company's literature tells what encryption technology they uses. S a n d y _________________________________________________________________ PLEASE RESPOND TO: ssandfort(a)attmail.com (except from CompuServe) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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["Vinton G. Cerf": Letter to Congress/RSA + DES]
by Marc Horowitz 14 Apr '93

14 Apr '93

Vint Cerf is a very well-known and respected person in the Internet community. I don't know if his testimony will mean anything, but it's interesting to read. Marc ------- Forwarded Message To: internauts:;@IETF.CNRI.Reston.VA.US Subject: Letter to Congress/RSA + DES Date: Tue, 13 Apr 93 20:26:01 -0400 Sender: cclark(a)IETF.CNRI.Reston.VA.US From: "Vinton G. Cerf" <vcerf(a)CNRI.Reston.VA.US> Dr. Vinton G. Cerf 3614 Camelot Drive Annandale, VA 22003-1302 11 April 1993 The Honorable Timothy Valentine Committee on Science, Space and Technology Subcommittee on Technology, Environment and Aviation House of Representatives Rayburn House Office Building Dear Chairman Valentine: I recently had the honor of testifying before the Subcommittee on Technology, Environment and Aviation during which time Representative Rohrabacher (R, California) made the request that I prepare correspondence to the committee concerning the present US policy on the export of hardware and software implementing the Data Encryption Standard (DES) and the RSA Public Key encryption algorithm (RSA). As you know, the DES was developed by the National Institute for Standards and Technology (NIST) in the mid-1970s, based on technology developed by Internatonal Business Machines (IBM). The details of the algorithm were made widely available to the public and considerable opportunity for public comment on the technology was offered. In the same general time period, two researchers at Stanford University (Martin Hellman and Whitfield Diffie) published a paper describing the possible existence of mathematical functions which, unlike the symmetric DES algorithm, could act in a special, pairwise fashion to support encryption and decryption. These so-called "public key algorithms" had the unusual property that one function would encrypt and the other decrypt -- differing from the symmetric DES in which a single function performs both operations. The public key system uses a pair of keys, one held private and the other made public. DES uses one key which is kept secret by all parties using it. Three researchers at MIT (Rivest, Shamir and Adelman) discovered an algorithm which met Hellman and Diffie's criteria. This algorithm is now called "RSA" in reference to its inventors. The RSA technology was patented by Stanford and MIT and a company, Public Key Partners (PKP), created to manage licensing of the RSA technology. A company called RSA Data Security, Inc., was also formed, which licensed the technology from PKP and markets products to the public based on the technology. The current policy of the United States places DES and RSA technology under export control. Because cryptography falls into the category of munitions, it is controlled not only by the Commerce Department but also by the State Department under the terms of the International Traffic in Arms regulations. Despite the public development of both of these technologies and their documented availability outside the United States over the last 15 years, US policy has been uniformly restrictive concerning export licensing. As the United States and the rest of the world enter more fully into the Information Age in which digital communications plays a critical role in the global infrastructure, the "digital signature" capability of public key cryptography is a critical necessity for validating business transactions and for identifying ownership of intellectual property expressed in digital electronic forms. Registration and transfer of intellectual property rights in works which can be represented in digital form will be cenral factors in the national and global information infrastructure. A number of parties are exploring technical means for carrying out rights registration and transfer, making use of public key cryptography as a basic tool. In addition, there is a great deal of current work on electronic mail systems which support privacy by means of encryption and support authenticity by means of digital signatures. One of these systems, developed in the Internet environment I mentioned in my testimony, is called Privacy-enhanced Mail (PEM) and makes use of DES, RSA and some other special "hash" functions which are integral to the production of digital signatures. For these various systems to be compatible on an international basis, it would be very helpful for the cryptographic components to be exportable on a world-wide basis. A number of vendors make produces relying on these technologies within the United States but often find it very difficult to engage in international commerce owing to the export licensing required for these technologies. Ironically, the technology appears to be widely available outside the US and also outside the COCOM countries, so US firms face both competition outside the US and export inhibitions in their attempts to develop worldwide markets. There are many valid national security reasons for limiting the export of cryptographic capabilities, since these technologies may aid an opponent in time of war or other conflict. Perhaps just as important, US intelligence gathering capability can be eroded by the availability of high grade cryptography on a worldwide basis. Recently, it has also been alleged that the world-wide availability of cryptography would also seriously impede US drug enforcement and anti-crime efforts. While these reasons seem sufficient, many have pointed out that the widespread accessibility to the detailed specifications of DES and RSA and availability and existence of software and hardware outside the US have long since done whatever damage is going to be done in respect of warfighting, crime or drug potential. This line of reasoning leads to the conclusion that our policies only inhibit legitimate commerce, but have little impact on the other concerns expressed. As in all such controversy, there is often some truth on both sides. The National Institutes of Standards and Technology (NIST), has offered alternative digital signature capability. Technical assessments of the alternative have turned up weaknesses, in the opinions of some experts. There is not yet an alternative to DES, unless it is to be found in NSA's Commercial Crypto Evaluation Program (CCEP) in which NSA proposes to provide algorithms which are implemented in hardware by industry and made available for civilian use. As I understand this program, NSA does not intend to release any details of the algorithms, leaving open questions about the nature and strength of the technology. Some experts will persist in the belief that such offerings have weaknesses which are deliberately built in and hidden (so-called "Trojan Horses") which will allow the agency to "break" any messages protected by this means. The critics complained loudly that the reasoning behind the design of certain parts of the DES algorithm (specifically the "S-boxes") was never made public and therefore that the algorithm was suspect. In fact, the DES has proven to be very strong - indeed, it may be that very fact which makes it so unpalatable in some quarters to permit its unrestricted export. It may be that the CCEP technology offered is satisfactory, but this is hard to tell without knowing more about its provenance. Presuming the wide availability of both DES and RSA technology, it seems to me appropriate and timely to re-examine US export control policy regarding these two algorithms. In all probability, any such review will require some classified testimony which will have to be heard in confidence by cleared members of your committee. I sincerely hope that the outcome will be favorable to use by US industry in international commerce, but even if the outcome results in continuation of present policy, it is timely to make such a review, in my opinion. Sincerely, Vinton G. Cerf ------- End of Forwarded Message

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how secure is secring.pgp?
by J. Michael Diehl 14 Apr '93

14 Apr '93

Yet another pgp question... We don't get any pgp news groups here. Since we need a passphrase to access our secret key, it is reasonable to think that our secring.pgp file is pretty secure, as long as our passphrase is notrivial. What am I missing here? Thanx in advance. +----------------------+----------------------------------------------------+ | J. Michael Diehl ;-) | I thought I was wrong once. But, I was mistaken. | | +----------------------------------------------------+ | mdiehl(a)triton.unm.edu| "I'm just looking for the opportunity to be | | Thunder@forum | Politically Incorrect! | | (505) 299-2282 | <me> | +----------------------+----------------------------------------------------+

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Sign-off
by sean＠gomez.Jpl.Nasa.Gov 13 Apr '93

13 Apr '93

Please remove me from this list. Thanks. -- Sean Barrett How many boards would the Mongols sean(a)pugsley.jpl.nasa.gov (fast) hoard, if the Mongol Hordes got bored? sbar(a)genie.geis.com (reliable) PGP key by finger or from key servers.

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Re: Modem encryption proposal
by karn＠qualcomm.com 13 Apr '93

13 Apr '93

Crypto synchronization seems to be a problem mainly in real-time appliations like digital voice, where you don't have a reliable protocol underneath you. I advocate two approaches that don't seem to have been pursued much yet, at least in the Internet: per-packet encryption (and possibly) authentication) just above the IP layer, and stream encryption just above TCP. The former technique has the advantage of denying your adversary the maximum amount of information, because only the IP header is in the clear. The transport header and all user data is protected, so an eavesdropper can't tell which applications are communicating. And with IP-in-IP encapsulation, you can even deny him knowledge about which machines are actually communicating - a network-level service analogous to anonymous remailers. With authentication, network level security also provides good protection against replay attacks. The latter technique (encrypting above TCP) has the advantage of being more efficient (it doesn't break Van Jacobson TCP/IP header compression), which may make it desirable for some interactive sessions. This is essentially how encrypted Kerberos Telnet works now, although I would like to generalize the service to work with any TCP client. Phil

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forward: cryptanalysis talk abstract
by david＠staff.udc.upenn.edu 13 Apr '93

13 Apr '93

Thought people might find this abstract of a talk being given here at Penn of some interest. Please let me know if I'm wrong <grin>. (And, no, I won't be attending; almost all of it would be over my head. What is in this abstract is probably as much of it as I could understand without considerable preparation <grin>). ------------------------------------------------------------------------ In article <119753(a)netnews.upenn.edu>, holland(a)central.cis.upenn.edu (Billie Holland) writes: > > Statistical Techniques for Language Recognition: > An Introduction and Empirical Study for Cryptanalysts > > Alan T. Sherman > Computer Science Department > University of Maryland Baltimore County > > In cryptanalysis, how can a computer program recognize when it has > discovered all or part of the secret message? For example, how can a > program recognize character strings such as ``Attack at dawn!'', > ``DES@RT ST\&RM'', or ``?tta????t d?wn'' as fragments of intelligible > messages? In the early days of cryptology a human would perform these > language-recognition tasks manually. In this talk I will explain how > to recognize language automatically with statistical techniques. > > Statistical techniques provide powerful tools for solving several > language-recognition problems that arise in cryptanalysis and other > domains. Language recognition is important in cryptanalysis because, > among other applications, an exhaustive key search of any cryptosystem > from ciphertext alone requires a test that recognizes valid plaintext. > Although I will focus on cryptanalysis, this talk should be relevant > to anyone interested in statistical inference on Markov chains or > applied language recognition. > > Modeling language as a finite stationary Markov process, I will adapt > a statistical model of pattern recognition to language recognition. > Within this framework I will consider four well-defined > language-recognition problems: 1) recognizing a known language, 2) > distinguishing a known language from uniform noise, 3) distinguishing > unknown 0th-order noise from unknown 1st-order language, and 4) > detecting non-uniform unknown language. For the second problem I will > give a most powerful test based on the Neyman-Pearson Lemma. For the > other problems, which typically have no uniformly most powerful tests, > I will give likelihood ratio tests. I will also discuss the > chi-squared test statistic $X^2$ and the Index of Coincidence $IC$. > > In addition, I will present the results of computer experiments that > characterize the distributions of five test statistics when applied to > strings of various lengths drawn from nine types of real and simulated > English. > > > This is joint work with Ravi Ganesan. Most of this work was carried > out while Sherman was a member of the Institute for Advanced Computer > Studies, University of Maryland College Park. > > Thursday, 15 April 93 > TOWNE BUILDING - 337 > 3:00 - 4:30 > -- david david(a)staff.udc.upenn.edu

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