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Pseudo-DC-net Project
by janke＠unixg.ubc.ca 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I am working on a project to implement a variation of a DC-net to be run over the Internet. I am posting this summary to find out if it overlaps with projects others are working on; to see what members of the lists think of the general ideas for the network I have in mind; and to see if anyone is interested in helping me out. The variation of a DC-net I have in mind will vary in three important ways from a true DC-net: Difference (1) (Pseudo-random numbers) It will use pseudo-random numbers in place of true random numbers. Difference (2) (Star shaped network) The graph of the network will be star shaped instead of completely connected. Difference (3) (MACs) Messages broadcast on the pseudo-DC-net will have a MAC appended in a key shared by the channel participants. Difference (4) (Encryption) Messages sent to the channel will be encrypted in a key shared by the participants. Because of these difference from a true DC-net I will refer to the network I have in mind as a "pseudo-DC-net". Difference (1) is desirable since current techniques for generating true random numbers on PC's are slow, and distribution of the resulting true random numbers is enormously consumptive in terms of bandwidth. Difference (2) is made possible by the use of pseudo-random number generators, and is desirable since it reduces the total number of messages that need to transferred. Difference (3) is desirable to identify messages broadcast by unauthorized parties to the network, and, as a side benefit, to help clients filter out collisions--- when two parties try to broadcast at the same time. Difference (4) is desirable so that eavesdroppers cannot determine what messages are being broadcast to the network. Difference (1) implies a downgrading of the level of anonymity from unconditional to cryptographic, and difference (2) opens the possibility for protocol attacks. I would like to break this project up into three parts: a formal protocol specification, a client implementation or implementations, and a server implementation or implementations. I would like the formal protocol specification to be publicly available to allow anyone to write their own clients and servers, and to communicate their criticisms of the protocol. The protocol will not dictate what pseudo-random number generator is to be used, although there will be a note of a rule to ensure that pairs of users are using the same generator for the "coin flips" they share. Similarly, the protocol should be flexible enough to allow the use of any reasonable length MAC. A general outline of the protocols I have in mind are as follows: Protocol (1) (Channel registration protocol) Channels will be registered with the server. A channel will be specified by a time frame in which a pseudo-DC-net is to be run; the IP address and port to which clients are to connect to join the channel; the length of each message block to be transmitted to the channel; and a channel ID. Protocol (2) (Pseudo-DC-net real-time protocol) The protocol for running the channel will consist of a series of "rounds". Each round will consist of the following steps: Step (1) The transmission of a round synchronization number from the server to the clients, along with a string of bits specifying the set of users connected. Old clients should make sure that the synchronization number is consistent with the synchronization number of the previous round. Step (2) Receipt by the server from each client of a block of input for that round. (If the user does not wish to broadcast, this will be the XOR sum of the next blocks in the the pseudo-random number streams shared by the user with the other users (call this sum S). If the user wishes to broadcast, it will be the encryption of the following: the XOR of S with a message consisting of the concatenation of the channel id, round number, message length, message, message padding, and MAC of these five components.) Step (3) Transmission from the server to each client of the XOR sum of the blocks received. Protocol (3) (Optional Payment Protocol) I would like to add the option for the server to charge e-cash for the administration of the channel. I have also thought about an extension in which messages to the server would be signed so that the server could prevent an unauthorized user from hijacking a connection and disrupting a channel. If you would like to help me out with this project, if it overlaps with something you are already doing or have done, or you just think my ideas are no good (or good! :) ), please let me know. I am especially interested in attacks in which the server lies about the round number or set of connected users. If this project is works out well, I would like to later work on protocols for voting using a pseudo-DC-net. Leonard Janke (pgp key id 0xF4118611) -----BEGIN PGP SIGNATURE----- Version: 2.6.3ia Charset: noconv iQEVAwUBMeFVY0MBIFf0EYYRAQErKwf+OcQjqoODovlRJZtrXuqTGeiRHTobFDa+ DFWEmGl+yditRBt9nAlCgXGiRkCXhqroX30M+SEVw02trc1eBMCeJUSvxB9d0pN6 9x3vDN/XB4Kj6kAuAypulBCa0f74Uim4nJvZDw7boEW/hXY3Yuf7d3mgOsNY/LRT p62FL24wnz8aeBAVYnE6SJp59u9Yssrvb2lez1IuKIdN8Rqx590Fwn1VBZ2oqGk8 6UucJkvTht7XmKPuckND+Lhq7jv1vVZKZD3NRe4Uy21JstwKwwpuVXVX98YlNc+Y a15wW4WstZIzsKuPrYVsLsb+wXsETp1sgp5jDkKQABfit7XS8FVC9g== =KZsI -----END PGP SIGNATURE-----

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Re: The Net and Terrorism
by tcmay＠got.net 17 Dec '03

17 Dec '03

Thanks for the fine comments (and the comments from your shrink-wrapped friend on Ritalin). A very few comments: At 8:16 AM 7/8/96, Arun Mehta wrote: >because you were taught hate, doesn't mean you won't outgrow it. My mother >was active in the freedom struggle against the British, and told me enough >horror stories that I grew up hating them. But once I met some perfectly >decent specimens, it evaporated. This is my experience, too, with using common sense in deciding which races, if any, to hate. >India is a large, diverse country with lots of injustice, poverty and other >problems. When we analyze what breeds terrorism, we find aspects such as: > >- Severe neglect by the government (i.e. problems keep getting worse): For >instance, the north east (which is east of Bangladesh, and has a long >history of militant opposition) had to agitate for a long time to even get a >railway line to connect them to the rest of the country. A case, of course, where the government set the policy on who to connect, based on votes and influence. In a market economy, regions get connected by rail when a market for goods to be shipped appears likely, when customers will pay for tickets, etc. (Until the last several decades, this is the way railroads and shipping in the U.S. expanded. J.J. Hill built the "Great Northern" rail line across the northern part of the U.S. without a dime of subsidy and without much interference by government.) >- Meddling by politicians: in Punjab, there was a Sikh regional party that >was quite strong. To erode its popular base, Indira Gandhi encouraged the >fundamentalists on its right. Similarly, Rajiv Gandhi's government helped >train the Tamil LTTE. Both paid for these blunders with their lives, at the >hands of the very groups they had once tried to foster. This "tactical move" of pitting one religious or ethnic group against another should be a lesson for the rest of us. Much better to take a hands-off attitude and essentially pretend that differences don't matter. (As opposed, say, to giving special privileges to Baptists, blacks, Catholics, etc.) In this regard, I think the U.S. got it "right" (though we are drifting toward a "minority rights" situation, which is sowing the seeds of Indian-style sectarian conflict, e.g., the riots in Los Angeles a few years ago). (Arun is now quoting someone else) >>The U.S. has a level of tolerance for diversity that I >>only recently came to >>appreciate. We hosted a foreign exchange student from Scotland (hardly >>culture shock to him), but he surprised me when he commented on how >>surprised he was that different groups of people were mixed together > >I've had a similar experience. I was part of the Indian delegation to a >couple of Amnesty International International Council meetings. In this >organisation, multiracialism and multiculturalism are heavily promoted. But >if you looked at delegations from Europe, even from countries with sizable >racial minorities, they were typically all-white. The US delegation, on the >other hand, had blacks, different kinds of Asians, Hispanics... and not by >design -- the US section leadership is highly "mixed", so they did not have >to think about multiracialism, it just happened. Of course, given the >"melting pot" ethos in the US, this is hardly surprising. Indeed, Americans are often branded as racist yahoos by the enlightened, racially-tolerant folks of Europe. They cluck at our "racial problems." However, America is a melting pot, as Arun notes. On a daily basis we interact with blacks, Asians, Mexicans, whites of all flavors, etc. Blacks, for example, are very well-represented in so many areas (not science and technology, for educational/cultural/image reasons--see Note if you want to hear why). For anyone who buys the UNESCO line about how American is a fundamentally racist society, a visit for a few weeks should clarify things. There is still a lot of racial separation, by choice and not by law, and economic disparities. But the fact is that the races mix on a daily basis, with little or no conflict. Music, sports, entertainment, business, etc. (Note: For various cultural and image reasons, science and technology are _not_ emphasized as careers for black children. Contrast the image of science in predominantly black environments with the image of science in, say, predominantly Jewish environments. The result is clear: blacks are severely underrepresented in these areas, and Jews are overrepresented in these same areas. Hey, I'm just citing a basic truth of our times, at least in this country. Similar statistics apply to Asians, with more than half of all U.C. Berkeley science and engineering undergrad students being Asian, and something less than 3% of them being black. The figures for who _graduates_ are even more skewed. There are various reasons for this. One of my pet peeves is how the terms "dweeb," "nerd," and "geek" are used to characterize science and engineering majors and professionals. Hardly terms that are likely to make a brother in the hood consider studying science!) --Tim May Boycott "Big Brother Inside" software! 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, Licensed Ontologist | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."

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InfoWarCon V: DC
by winn＠Infowar.Com 17 Dec '03

17 Dec '03

* * * * * * * P L E A S E D I S T R I B U T E W I D E L Y * * * * * * * InfoWarCon 5, 1996 Electronic Civil Defense for the 21st. Century The Convergence of the Commercial and the Military Sectors: Vulnerabilities, Capabilities and Solutions September 5-6, 1996 Washington, DC Sponsored by: Winn Schwartau, Interpact, Inc./Infowar.Com National Computer Security Association/NCSA.Com Robert Steele, OPEN SOURCE SOLUTIONS, Inc./OSS.Net Sponsoring Organizations: Command Software Systems Digital Equipment Corporation Norman Data Defense IBM Phillips Publications Jane's Information Group Historically, civil defense has meant to protect citizenry against hostile military actions. Today, with the specter of Information Warfare representing new challenges to late-industrial and information age nation-states, the rules have radically changed. Societies are rapidly migrating to increased dependance upon four critical interrelated infrastructures and adequate methods of protection must be developed: - The Power grid is the basis of most of modern society. With it gone, not much else happens. If you think this is just a matter of building more generators, think again--what happens if the factories that *make* the generators are taken down, too? - The Communications infrastructure: land, sea, air and satellite. 95% of military communications go over the public networks, and 100% of all financial and industrial communications. Is it worth protecting? - The Global Financial structure depends upon the first two infrastructures, and is perhaps the most vulnerable to theft and denial of service attack. 99+% of all "wealth" is digital--what happens if it vaporizes? - Transportation systems rely upon the other three. The air traffic systems require both power and communications to manage the thousands of airplanes in the sky. What happens to the thousands of airplanes in the air if air traffic control across an entire country goes down? Without all of these infrastructures properly and reliably functioning, the private sector and the national security community cannot function. No heat, no air conditioning, no food distribution, no light, no radio or TV, no Internet. Are we prepared? Do we have a a crisis response for the day money as we know it vanishes? Electronic Civil Defense will soon become a critical component of any nation's well being while the needs of both the private sector and government converge. The convergence of military and civilian interests that Mr. Schwartau predicted two years ago is happening before our eyes. Defensive and commercial postures have so intertwined as to make them indistinguishable. This Fifth International Conference on Information Warfare is an unclassified, open source forum, and will examine the myriad questions of Electronic Civil Defense from the US, International and multi-cultural perspectives. Our seasoned experts will work with InfoWarCon5 delegates to outline a framework for the vulnerabilities, threats, risks and solutions for Electronic Civil Defense. From this conference participants will be able to draw critical insights which will improve their own legislative, regulatory, financial, and operational readiness and security. Last year's Washington InfoWarCon brought together over 600 people and was covered by CNN among other major media organizations. This year key world players in information warfare from the economic, military, and law enforcement communities of over 30 countries are expected to participate. Be prepared for highly interactive sessions with plenty of audience participation. Please bring your opinions and be ready to discuss them with us all! PRELIMINARY SCHEDULE September 4, 1996 16:00 - 20:00 Registration Begins 18:00 - 20:00 Sponsored Reception for attendees, speakers, sponsors and the press. Light food fare and liquid refreshments. Meet Mr.Schwartau, Mr. Steele, Dr. Kabay and many of our other world-class speakers. September 5, 1996 6:30 - 7:50 Registration 7:50 - 8:00 Welcoming Comments and Administration: Dr. Peter Tippett, NCSA Winn Schwartau, Interpact, Inc. 8:00 - 8:30 Keynote Presentation: "National Security in the Information Age" Senator William Cohen (R-Maine) * 8:30 - 9:00 "A Commander in Chief's View of Rear-Area, Home-Front Vulnerabilities and Support Options." General John J. Sheehan, U.S. Supreme Allied Commander, Atlantic, Commander-in-Chief Atlantic Command 9:00 - 9:30 "Global Finance: Protection in the Age of Electronic Conflict" Colin Cook, V.P. Information Security, Citibank * 9:30 - 10:00 "We Can't Do It Without the Private Sector" Ken Minihan, Director, NSA * 10:00-10:30 Break 10:30-11:45 National Policy Reviews of Electronic Civil Defense Programs Ms. Sally Katzen, Administrator for Information and Regulatory Affairs, Office of Management and Budget, USA Dr. Anders Eriksson and Peter Wallstroem, National Defence Research Establishment, Dept. of Defence Analysis: Sweden Dr. Leroy Pearce, Canada, What is the current thinking in Electronic Civil Defense? How do plan on protecting our citizens against invisible unnamed assailants? What are the top policy makers planning for? International experts will present their views as well. 11:45 - 13:15 Sponsored Lunch 12:30 - 13:00 Luncheon Address 13:15 - 14: 30 Breakout Sessions A1 - A4 A1 A Military Briefing: The Electronic Projection of Power in a C4I World Moderated by General Jim McCarthy, USAF (Ret) Barry Horton, Principle Deputy Assistant Secretary of Defense for C3I * Captain Patrick Tyrrell, Assistant Director, Information Warfare Policy, Ministry of Defence, United Kingdom A2 Protecting the Global Financial and Communications Infrastructures: Weaknesses at the Transport Layer Ron Eward, Martech, Inc. One scary session. Forget about HERF Guns and hackers. Mr. Eward will tell us how to wreak disaster with a few well placed pick- axes, from New York to Palermo to Taipei. An incredible research effort with global on the generally forgotten physical underpinnings of Cyberspace. Do not miss his tremendously important findings. Messrs. Eward and Schwartau upcoming book on this overlooked topic will shake the financial global community. A3 Media Manipulation, Perception Management and PsyOps Moderated by Dr. Mich Kabay, NCSA Mark Bender, ABC News * Jim Roberts, SOLIC Neil Munro, Washington Technology How can a nation-state use the media to bend the will of an adversary, or leverage its own position prior to, in or after a conflict? Who is really using who? A4 National Defense University Session Moderator - Dr. Dan Kuehl, Professor, NDU Top students from the School of Information Warfare and Strategy, the Nation's top-level school for potential flag officers in the IW arena, will discuss their findings and concerns. 14:30 - 15:00 Break 15:00 - 16:15 Breakout Sessions B1-B4 B1 - Emergency/Disaster Planning for the Effects of Information Warfare: Moderator: Mark Aldrich, Chief Infosec Engineer, GRC International, Inc. Michael Logan, Federal Planning Associate, American Red Cross William W. Donovan, CISSP, FEMA Ken Barksdale, Association of Contingency Planners Assume the worst happens, and an infowar assault takes down major life sustaining portions of the infrastructure. What do we do about it? How do we minimize the damage and protect the victims and citizens? These esteemed experts will tell you what they think and then invite your comments. B2 Legal Liabilities and Responsibilities in Information Warfare Danielle Cailloux, Judge, Committee on Intelligence, Belgium Charles Dunlap, Judge Advocate, USAF Kenneth Bass III, Cyber-Attorney, Washington If a company is attacked and it loses significant assets, what are the recourses of the stakeholders? How do we measure and evaluate the losses and responsibility? On the military side, what constitutes an Act of War and what steps are necessary to formulate a response? B3 The Forensics of Information Wafare for Law Enforcement Moderated by Michael Anderson, New Technologies Investigation Division Howard Schmidt, Director, AF Office of Special Investigations Ken Rosenblat, Santa Clara County Prosecutor, Author "High-Technology Crime: Investigating Cases Involving Computers" How can you tell you are under attack? Once you determine you are, how do you make a case which will stand up in court? How do you collect evidence? How do you involve law enforcement without compromising your efforts? Experts share years of experience with you. B4 Naval Postgraduate School Session Moderator: Dr. Fred Levien, NPS Top field grade students from the Naval Postgraduate School in Monterey, California will present InfoWar papers and concepts. 16:15 - 16:45 Break 16:45 - 18:00 The Hacker/Underground and Social Engineering Moderated by: Nic Chantler, Australian Intelligence (Ret) Andy Mueller-Maguhn, CHAOS Computer Club, Germany Chris Goggans, co-founder, Legion of Doom, USA John Gilmore, Electronic Frontier Foundation If you've ever wanted to know how hackers think; what makes them tick and how they became the first Information Warriors, here are the people who can answer your questions. These sessions are among the most popular at every InfoWarCon. Gilmore will present his unique concepts for Defensive Information Warfare. 18::00 - 20:30 Sponsored Reception/"Live Hackers" Off-Line September 6, 1996 6:30 - 7:50 Continental Breakfast 7:50 - 8:00 Opening Remarks and Administration 8:00 - 8:30 "Domestic Law Enforcement and Electronic Civil Defense" Louis Freeh, Director, FBI * 8:30 - 9:00 "The Convergence of Military and Civilian Defense" General Jim McCarthy, USAF (Ret) 9:00 - 9:30 "What is National Security?" Michael R. Nelson, Ph.D. Special Assistant for Information Technology White House Office of Science and Technology Policy 9:30 - 10:00 "Building a Society from the Net Up" Pedrag Pale, Chairman of the InfoTech Coordinating Committee, Ministry of Science, Technology and Informatics, Croatia 10:00-10:30 Break 10:30-11:45 The Russians are Coming Moderated by: Greg Treverton, Director of National Security Program, Rand Corporation From academia to the military to their business community, the Russians have been thinking long and had about Information Warfare. Here's what they have to say. Get front row seats and be ready to ask your questions. Dr. Victor I. Solntsev, Assoc. Prof. Moscow State Tech. Univ. "Information Warfare and Human-Operator Security" Dr. Dmitry Chereshkin Russian Academy of Sciences; Editorial Board, "Information Infrastructure and Policy." Dr. Georgy Smolian Russian Academy of Sciences and Scientific Council "Democratization of Russia and Information Security." 11:45 - 13:15 Sponsored Lunch 12:30 - 13:00 Luncheon Address 13:00 - 14: 15 Breakout Sessions C1-C4 C1 Corporate Civil Defense: Moderated by Don Sortor, Director Security Prgms, Corp. InfoSec., Motorola, Inc. A team of cross-industry experts from the primary infrastructures, will examine how industry and government can and should interact in the event of an Electronic Pearl Harbor. What is the role of the company and its management? What policies should be put into place to prepare for the malicious Acts of Man? How should the government work with the private sector to mitigate damages? These experts will set you on the right track. C2 Denial of Service in the Private Sector: The Nuclear Weapons of the Information Age: Magnetic Weapons from the Military to Electronic Pipe Bombs Carlo Copp, Defense Analyst, Australia Kelly Goen, Penetration and Security Engineer Get Seats Early! Magnetic weapons; directed energy weapons; HPM; HERF Guns; electromagnetic pulse cannons and EMP. Learn about the latest in high energy weapons systems and how they can be used to attack and destroy critical electronically based infrastructures. Then find out what the terrorist can do with home-brew electronic pipe bombs. C3 The Net Under Attack Dr. Dorothy Denning, Chair, Computer Science Dept., Georgetown Univ. Jim Christy, Permanent Subcommittee Investigations U.S. Senate (And USAF OSI) What makes an attack on the Internet and what do we do about it? Ms. Denning is an internationally recognized expert who will guide us and her panel of experts through the maze of possibilities. Incredibly valuable for security professionals. C4 USAF School of Advanced Airpower Studies Moderated by Col. Richard Szafranski, USAF, Air War College National Military Strategy Col. Szafranski and his top students will discuss their views, opinions on Information Warfare. The USAF SAAS has produced some of the most revolutionary papers in IW, including the now globally recognized papers on taking down telecommunications and national power systems. 14:30 - 15:00 Break 15:00 - 16:15 Breakout Sessions D1-D4 D1 Anonymous Global Banking: Pitfalls and Solutions Moderated by Bruce Schneier Kelly Goen, Security Engineer Eric Hughes, Cypherpunks Phil Zimmermann * How does anonymous international banking work? Is it merely a front for Criminal Central? Or is there a true value? How do conventional banking institutions view it? What about cryptographic solutions? Are your funds "naked on the Net today? Come see for yourself! D2 The Ethics of Information Warfare Moderated by Winn Schwartau Col. Phil Johnson, Judge Avocate, USAF Dr. Dan Kuehl, NDU While CNN is looking over your shoulder, as a military commander, here is your choice: either use a precision smart bomb which will immediately kill 20 civilians for the world to see. Or, use a non-lethal IW weapon, no immediate TV deaths, but a predicted 200 civilian collateral fatalities within 30 days. What do you do? The Ethical conundra of Information Warfare will be examined from all perspectives. Or: you have been attacked anonymously--you suspect one party, without proof--another attack is coming. What now? Should we develop new intelligence capabilities to permit precision detection and response in cyberwar? D3 National Information Assurance: Cooperation is the Key to Safeguarding Communications, Power and Transportation Moderated by: Major Brad Bigelow, Office of the Manager, National Communications System Jeff Sheldon, General Counsel, Utilities Telecommunications Council Steve Fabes, Director of Electronic Delivery Services, BankAmerica Carl Ripa, VP National Security/Emergency Preparedness, Bellcore Experts from the major civilian infrastructures will discuss how past cooperation between industry and government has echoed economic realities. The bulk of the nations information infrastructure is not under the economic or regulatory control of the Federal government. So, how do we maintain a healthy balance between private initiative and legislative and regulatory actions? Today there is no "due diligence" standard which requires that communications and computing services be guaranteed in terms of security and data integrity. Our panel will provoke an active discussion of remedial cooperative measures. D4 "Understanding and Defending Against Industrial Espionage and Information Terrorism." Tom Fedorek, Managing Director, Kroll Associates New York* Matt DeVost TITLE COMING Charlies Swett, Acting Deputy Director for Low-Intenstity Conflict Policy, Office of the Assistant Secretary of Defense for Special Operations and Low-Intensity Conflict A look at how modern espionage and information is conducted, why it's done and who's doing it. How much can it cost your company and how can you tell if you're targeted? Do not miss this fascinating session which is expected to feature the Kroll Managing Directors from Paris, London, and New York. 16:15 - 16:30 Break 16:30 - 17:00 Wrap Up: "What is War?" Moderated by Dr. Mich Kabay, NCSA General Jim McCarthy, USAF (Ret) John Petersen, President, The Arlington Institute You - The Audience An exciting 'don't miss' interactive audience session. What a closing! (* Speakers with an * have been invited but have not confirmed as of June 28, 1996.) HOTEL INFORMATION: Crystal Gateway Marriott 1700 Jefferson Davis Highway Arlington, VA 22202 The Crystal Gateway Marriott is offereing a special conference rate of $129 single/$139 double occupancy. This rate is good until August 14, 1996. 703-920-3230 (Voice) 703-271-5212 (Fax) CANCELLATION POLICY After August 9th, any cancellation will incur a $100.00 processing fee. If the reservation is not cancelled and no one attends, the full registration price will be charged. Substitute attendees are welcome. InfoWarCon '96 Registration Form: Name: ___________________________________________________________ Title: ___________________________________________________________ Org: ___________________________________________________________ Address: ___________________________________________________________ Address: ___________________________________________________________ City: ___________________________________________________________ State: _______________________________ Zip: _____________________ Country: __________________________ Email: ________________________ Phone: __________________________ Fax: _________________________ FEES: Payment made BEFORE August 9, 1996: ( ) 595.00 NCSA Members/OSS '96 Attendees ( ) 645.00 All others Payment made AFTER August 9, 1996: ( ) 645.00 NCSA Members/OSS '96 Attendees ( ) 695.00 All others Make checks payable to NCSA, or Charge to: ( ) VISA ( ) MasterCard AMEX ( ) Number: ___________________________________________ Exp date: ___________________________ Signature: ___________________________________________ MAIL OR FAX OR EMAIL REGISTRATION TO: National Computer Security Association 10 South Courthouse Avenue Carlisle, PA 17013 Phone 717-258-1816 or FAX 717-243-8642 EMAIL: conference(a)ncsa.com For more information about NCSA: WWW: http://www.ncsa.com CompuServe: GO NCSA EMail: info(a)ncsa.com Version: 1.10 Peace Winn Winn Schwartau - Interpact, Inc. Information Warfare and InfoSec V: 813.393.6600 / F: 813.393.6361 Winn(a)InfoWar.Com

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Synchronization Attack on Pseudo-DC-net's
by janke＠unixg.ubc.ca 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Here's an easy attack on a pseudo-DC-net that I thought up over lunch if the clients trust the server to be honest in telling both the round number and who is on. Let Stephanie be the person running the server, and let Alice and Bob be two users. Let f(n) be the pseudo random function they share. Assume that Stephanie knows their secret encryption key. It is then possible for her to compromise their anonymity as follows: First Alice joins the net, and Stephanie tells her that it is round 100 and Bob is on. Alice sends a messages. Stephanie sends back some random junk to Alice to convince her that there was a collision. Alice backs off for a few rounds. Stephanine now receives f(101), f(102), f(103), etc. and then tells Alice that Bob has left. Alice leaves now. Later Bob joins. Stephanine tells him that it is round 101 and Alice is here. Bob starts talking right away, sending three message: f(101) xor M1, f(102) xor M2, and f(103) xor M3. From this Stephanie is able to recover M1, M2, and M3 by xor'ing f(101), f(102), and f(103), which she has from before, back in. Bob has completely lost his anonymity! Thus, it looks like trusting the server for both who is on and the round number is a bad idea! It might be possible to remove the need for a round number if the number of seconds since channel creation is used instead, and the clients are time synchronized. In that case running the pseudo-DC-net on top of UDP might be preferable to running it on top of TCP. Can anyone think of an attack if the server is just trusted for a list of who is on? If there is one, I guess new clients could ask for signed messages of who is on: "It is 456 seconds since channel creation, and, I---Alice---am on. (signature)". That would complicate the protocol, of course, and cost Nancy---a new client---some time in verifying the signatures. Good attacks so far! Keep 'em coming. :) Leonard Janke (pgp key id 0xF4118611) -----BEGIN PGP SIGNATURE----- Version: 2.6.3ia Charset: noconv iQEVAwUBMeF6nUMBIFf0EYYRAQGITQf/U0Wjpsyb7XpG6uCVFCPNaAYVIJpLeEyk Mxl6X/TQPhJFRclbRJwFoWfwH46M2le/QKHu6nFFjioyYbXofaLWqDeOa61XY5/c 4law80/xxAg9IdzoQp4mAz6QOvToMCOlNE21MCL8YlPrrdhIL4MfAH9gpU8+Otui IH1S5VB7TGE6ttZEx18sKdBUxYeJeU4jrXb4Uj2HEN5inLrhJBic/fsZ0hZXjCAH 5kbZLI8sf+leLyoW03qILeVl8jjYuPy/z16MsY2SDzJ3hFv8nngT9+fzVItX7sO2 ngvqvyUW4SIWfK8XwRWUiMFW7i7gyMcKteSSEJBaEdOZNcGUvXY+5Q== =jmVk -----END PGP SIGNATURE-----

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Re: [RANT] Giving Mind Control Drugs to Children [RitalinPunks]
by anonymous-remailer＠shell.portal.com 17 Dec '03

17 Dec '03

Something like 10% of ALL public school students in Tennessee are on Ritalin. Presumably, the percentages are similar in other states. I have trouble believing there are so many kids suddenly suffering from a disorder that wasn't even discovered until a few years ago. The following rant from a Ritalin user may be of interest (though not too relevant to cryptography): ************************************************************************* Occasionally I will see something about the practice of giving kids RITALIN for alleged attention-deficit disorder. I can't think of better evidence that the owners of the schools and the world are trying to destroy the kids in this country. I was big drug-taker. I've also had occasion to receive medication by prescription. I wil admit that I took a lot of amphetamines. Speed that is. I liked it and took it frequently, so I can attest that it has some very attractive char-acteristics that anyone taking it could not help but like at the time. It also has a gigantic letdown that is nearly intolerable. This discomfort leads ANYONE to do something to alleviate it. It's probably a matter of personal preference as to whether the discomfort of the letdown outweighs the positive feeling of the high. If not, people will keep taking speed. Now for reasons, I also had a prescription for ritalin. You know it's a controlled substance. The fact is it's an amphetamine derivative and imparts nearly the exact same experience, though not as sharp-edged. It has the high and the letdown. And people undoubtedly make the same kinds of decisions as is the case with amphetamines. They say that ritalin has a paradoxical effect on kids - meaning, I suppose, that the reasons that make it a controlled substance for adults doesn't apply to kids. Then they say in the same breath that ritalin treats disorders in the ability to concentrate or to pay attention, which are the exact things that speed and ritalin accomplish in adults. Both of these allow someone to focus exclusively on one task in an enjoyable state of mind and body and accomplish it. Any nervousness is just left over from the channeling of all the generated energy into one task. What is created is not only the false sense of security but the false ability to accomplish things. As time goes on, one aspect of the letdown is the now- understood knowledge that speed is generating false successes. This is a depressing realization that can have detrimental ramifications beyond anything to do with the drug. In college, say, false successes on exams are acceptable and desired because this is one occasion in which performance is measured. But when someone's life consists of false successes, false interactions, and false experiences - and the fact that these are false is well-realized - the result can be a very unhealthy individual self-conception whose validity is proved and reproved constantly as amphetamine use continues. I heard recently that now educators and other quacks find that ritalin enhances performance for everyone (I just said that), and they're thinking of prescribing it for that reason. This kind of poisoning of the self-concepts being developed by kids will create a generation of suicidal invalids. The idea is outrageous. This has gotten extremely long, and I wasn't planning on it. But this ritalin thing is so insidious and is so OBVIOUSLY meant to do harm that I have to write this long thing about it. The whole attention-deficit disorder is a fabrication that traitors use to pump kids full of controlled substances. Now i saw yesterday that kids not on ritalin are paying those who have it, stealing to get it, killing to get it, and on and on. Ritalin is speed, and the idea that educators, doctors, and other alleged public servants are colluding in this way to cripple kids into thinking they have no innate skills and no ability to function without a drug is one of the worst things I have come across in my entire life.

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Re: CDT Policy Post 2.27 - No New News on Crypto: Gore Restates
by jim bell 17 Dec '03

17 Dec '03

At 01:47 PM 7/15/96 -0700, David Sternlight wrote: >>Despite trying to hide behind the smokescreen of calling the >>government's GAK position "voluntary," we all know that they are trying to >>misuse their influence to gently force us to use GAK, if by no other means >>that forcing the taxpayer to pay for the system as they have done already. > >I agree, though I would not have phrased it in such an offensive way. Please explain why you think my comment above is phrased "in such an offensive way." Hint: If I'd really wanted it to be "offensive," I could have easily done that. >This isn't some conspiracy of evil but people with a legitimate policy >disagreement. I notice your insertion of the term "legitimate." As opposed to what? Do you mean that you acknowledge that there is such a thing as an ILLEGITIMATE policy disagreement? How can we tell the difference? And there goes that word, "policy," again! Containing with it, the assumption that governments (despite ostensible freedom of speech) have some sort of authority to regulate encryption. >>The opponents of GAK, on the other hand, are not denying to anyone the >right >>to implement a truly voluntary "key-escrow" system, or more likely many >>privately operating ones. > >I disagree again. It is evident from the effort to shoot down Clipper I, >which WAS voluntary, that this is another case of your version of >"voluntary". If an offeror, even the government, offers something voluntary >and you don't like it, you attempt to suppress it. It's kinda like "freedom >of speech only for those who agree with me". Huh? Developed in secret (secrecy, not merely for the technical details, but also for the broad overall concept: the former might have been justifiable to some people, the latter was not!), using stolen tax dollars, and presented as a fait accompli to the public. Oh, one more thing: Apparently designed to NOT be able to talk to non-escrowed encryption systems, in an obvious attempt to freeze out competition. The government was trying to misuse its influence here. Obviously some new strange usage of the word "voluntary" that I wasn't previously aware of. >> However, such systems will be a service for the >>customer, not the government, and the key will almost certainly not be >>provided to the government on request, and in fact the key will likely be >>stored in an encrypted form that the government won't be able to use. > >To the contrary, business records are always available on legitimate >subpoena by the government, There you go again with that word, "legitimate." Give me an example of an "_illegitimate subpoena_," will you? One that someone is not obligated to fulfill. What?!? You can't? Then why did you use the term in what is obviously (to you) a redundant fashion? > and this would include escrowed keys. YOU don't >have to like it, but it's the law. Not currently it isn't. Laws concerning "escrowed keys" haven't been written, and in any case since they don't have to be stored in the same legal jurisdiction, cooperation with a given set of authorities is not only not guaranteed, but isn't wise. Besides, the only thing I see in the US Constitution which compels a person's participation in and cooperation with a trial is a right of defendants to have witnesses appear in their _defense._ I see no corresponding right on the part of the prosecution to compel ITS witnesses to appear. And you ignored the part about the ENCRYPTED stored keys. If they're encrypted, then even if they're presented to the police, they won't be able to use them, law or no law. Given a choice, I think most people would prefer to use an "escrow agent" (if they chose to use one at all; which I doubt) that is either guaranteed to be uncooperative to the government, or one which CAN'T be cooperative, because the material it has is not in a form useful to the cops. As long as key-escrow is TRULY "voluntary," in the broadest and most accurate sense of the word, market forces will migrate to a practice which is best for individual customers as individuals. >>Quite simply, we do not require your "assent." You should be trying to get >>OURS. > >"Silence does not constitute assent" to your personal attacks, your policy >assertions, and what I think to be your misrepresentations of fact. I was >not speaking of assent to GAK in that sentence. > >I think your attempt to pseudospeciate me and create an "us and him" >situation in this group is bound to fail with those who have paid attention >to what I think and say, particularly my most recent thinking. On many >matters we are agreed at bottom. However, I place high value on policy There you go again with the word, "policy." Jim Bell jimbell(a)pacifier.com

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DIAL: directed information assembly line
by Vladimir Z. Nuri 17 Dec '03

17 Dec '03

over the past few months I've been intermittently posting some snippets and fragments of ideas on a new information processing system. I've codified most of what I was talking about into a semi-formal protocol description. I think this has tremendous potential for wide applications, and I suspect many of these ideas below are already being used in many diverse contexts but have not been unified into a single specification (which I think will increase their value and use signficantly). I suspect something like the following is actually going to be a natural, inevitable evolution of the current "information infrastructure" and cyberspace-- i.e. something like the following is going to evolve whether I personally work on it or not, or whether future designers see this particular essay or not. anyway, I will try to incorporate comments from correspondents into future revisions. I would love to put together a group of people interested in continuing to develop this although that's probably premature at this point. thanks to everyone who has (unwittingly) contributed to this so far based on responding to my earlier essays. === DIAL = introduction = terminology: flits, floutes & bloxes = fault tolerance = tracing = time estimation = common bloxes = implementation = examples introduction == The industrial revolution was driven by specific technologies. Similarly, the "information revolution" is now in full pace using a different array of new tools. However, it is unlikely that all information processing tools have been invented yet. This paper is a preliminary sketch of one such potentially significant tool called DIAL. DIAL stands for "directed information assembly line". This document contains a description of this novel information processing architecture. This proposal outlines the idea and contrasts it with existing systems, showing how it highlights certain aspects of data processing that are not specifically addressed in, but seem to be implied by, other existing tools. The system can be viewed variously as a programming environment, a monitoring system, a revision control system, a quality assurance and quality control mechanism, a fault tolerant computing system, a workflow (re)engineering technology, a company intranet routing algorithm, an operating system based on virtual reality, etc. terminology == DIAL is something like a "dataflow" oriented system. This document will not describe any specific implementation of the DIAL concepts (such as giving a language syntax) but instead focus on its abstract properties which can be implemented in multiple ways. There are 3 basic components in the DIAL universe: "flit" - a flit is a unit of information that has an associated DIAL state. The information can change over time. One aspect of state is "location". "flit" stands for "fleeting bit", i.e. a piece of data that can "move". The number of binary bits allocated to a flit may vary per flit or over time. "floute" - a floute is a "flit route" or a path that a flit can take. Conceptually flits move through the flouts. A flout can be implemented in various ways, such as "last in, first out", "first in, last out", a pool of data, etc. "blox" - a blox is a "black box" or a component that changes the information content of a flit. Bloxes are connected to floutes. The DIAL system is recursive in that any of the 3 basic objects can be contained or encoded in the 3 objects. For example, flits can contain flits, bloxes can contain further floutes and bloxes, etc. Conceptually, a DIAL system is a directed graph, with nodes called "bloxes", edges called "floutes", and a superimposed set of things called "flits" that can, over time, "move through" the network. In many cases flits have a natural analogy to messages being passed through the system. Bloxes contain a single internal state, like a regular automaton. They can send requests, and respond to, memory bloxes. DIAL is unlike a programming language in that "time" is considered a key property of what it models. Many languages handle the concept of time implicitly through the use of variables. But programming languages have a computation-centric view of processing, such that programs are seen as directing and operating on data. In DIAL, data is seen as flowing through components, a data-centric view. fault tolerance == To be implemented correctly, the state of a DIAL system at any given time is incorruptable. All operations have total integrity. The system is designed to coordinate unreliable subprocesses and must itself be reliable. In DIAL, a blox is roughly analogous to some kind of process. The process may or not be entirely computational. The blox models an unreliable process. The process is activated when a flit approaches the blox from a connecting floute, at which point the flit "enters" the blox. DIAL handles the protocol of informing the blox (or rather, the process represented by the blox) of the presence of the flit. DIAL keeps track of all flits that are currently being processed by bloxes. The blox should process the flit and push the flit into some other floute which signals it has successfully operated on the flit. Combinations of flits at inputs can be processed, and multiple outputs are supported. The DIAL system allows processing time limit rules to be associated with flits, floutes, and bloxes, such as a floute assigning time limits to flits that move through it, time limits associated with all flits going through particular bloxes, or time limits attached to flits. (The system will have a precedence to these rules.) The motion of flits through floutes is handled by the DIAL system and is incorruptable. Flits can "pile up" in floutes if not processed by connecting bloxes as rapidly as they accumulate. All bloxes may have different amounts of processing times on incoming flits. When a blox fails to "return" a flit in the time limit, the DIAL system can be programmed to automatically take particular countermeasures. The countermeasure programs are associated with flits in the same way the expiration time is (via the flit, a floute, or a blox, and having precedence rules). - DIAL can ask the blox, "have you heard of this flit". The blox can reply, (1) "yes, I am still working on it", or (2) "no, I have not heard of it". The rules can specify possibilities such as resubmitting the flit, cancelling the flit processing and redirecting it elsewhere, propagating other flits into floutes (which might represent message(s) sent to "failure controllers"), etc. - The blox may reply, "the flit has corrupted the blox". This may happen in systems without transaction integrity. Again rules can automatically be followed to try to "clean up" the system by propagating new flits to particular floutes or possibly resubmit the flit. - The blox may not reply. Again, rules for countermeasures can be programmed into the DIAL system. tracing == All flits have unique IDs that can be traced. At any time a query can be sent to the DIAL system, "where is so-and-so flit?" and the system will describe the exact location of the flit. Flits can never vanish, even when bloxes fail to operate correctly. Every flit has a history as well. The flit may contain different information at different times. The system allows some number of earlier information states of the flit to be accessed. Information about the past flow-path of the flit and each associated change in contents (prior and subsequent to entry and exit of a blox) is available. This could be called a "replay" feature. In a query of a DIAL system, it may actually reply, "the flit was deleted", although its earlier states would still be accessable. Another possible response is, "the flit moved out of this DIAL system", but again some number of its penultimate states, while it was still "inside", would still be accessable. Again, customizable rules determine how much history is available. General queries such as "locate all type [y] flits that have not moved within [x] time period" are supported. Past histories of the flits that have moved through flouts and bloxes are also available. The system can support some degree of "global or local rollbacks" in which prior processing flows are reset, redirected, restarted, etc. An ability to locate components based on traffic is supported, such as floutes where current flit queue lengths are of some size, etc. The system allows the assignment of arbitrary version numbers with particular flit states that are also allowed in queries. time estimation == An implementer of a DIAL system might support specialized queries called "time estimates". A flit is passed into a system with a special flag that indicates processing time should be estimated but results should not be computed. The flit flows as far through the system as possible and records time estimates as it passes the bloxes. When it finally emerges, cumulative statistics on the time estimates that would be associated with an actual processing of the flit are available to the requester. Common bloxes == - extracter/combiner Bloxes to extract flits, floutes, or bloxes encoded in flits are available, as well as to create flits that encode any of the same objects. - warehouse The DIAL system can support a flit warehouse in which all flits are stored when they are not being propagated elsewhere through the system. The warehouse is a blox that responds to flit queries in the form, "move flit [x] into floute [y]". (The motion of the flits into and out of the warehouse resembles the checkin and checkout task of RCS software.) - create bloxes In a static DIAL system, all bloxes and floutes are predetermined and fixed. In a dynamic system, the bloxes and floutes may change over time. This is accomplished by feeding special flits into bloxes that can create other bloxes and floutes as their result. Other bloxes can connect them in specified ways. The dynamic system is far more complex and is reserved for specialized situations. - rerouter A special rerouter blox is useful for dealing with new versions of other bloxes. A frequent problem that arises with new versions of software (i.e. a new blox) is that it is incompatible or has bugs. The rerouter blox is capable of rerouting a request to a new version of a blox to an older version when problems arise in the processing. - tester Often results output from bloxes are to be tested for consistency to ensure the bloxes are functioning properly and not returning spurious results. - tester/comparer/rerouter Another useful blox for fault tolerance can take the results of two other bloxes and compare them for discrepancies. Flits output from a new version of a blox could be compared with the flits from the previous version, and automatic actions be taken on any discrepancy (such as passing through the old version while flagging the exception). The comparer allows the system designer to more elegantly deal with regular "upgrades". In fact it is the embodiment of automated regression testing. - isolater Often input of flits is batched into groups, and some flit in the group may cause problems in the processing, but further detail in revealing the exact "bad" flit is not available. The isolater can automate this process in an algorithm that resembles the classic linear search. The input batch into a blox is consecutively split into halves by the isolater until the smallest erroneous pieces are isolated and hilighted. - global versioner Often a system with many bloxes has new versions of the bloxes, and there is need in globally switching control to new bloxes. This can be accomplished with the use of a special global versioner blox. It can keep track of the different versions of all bloxes in a given DIAL configuration, and switch between configurations. - bad blox isolater Combining many of the previous bloxes, a special system that automatically isolates new versions of bloxes that fail to be backward and/or forward compatible is possible. This is a direct implementation of the software development pipeline. implementation == The DIAL system should be implemented graphically and visually. A corresponding language specification to describe a DIAL network is possible and desirable, but a visual or graphical interface to any operation should always be possible; likewise a representation of all DIAL states should be supported. Ideally, the DIAL universe could be visualized in a 3d virtual reality, and a person could physically "grasp" and manipulate all the basic objects (flits, floutes, bloxes). The one-to-one visual representation of DIAL and its states is a key aspect of its accessability and usefulness. There should be in principle no memory limits on the core DIAL entities: flits, floutes, or bloxes. Limits in implementations such as "a maximum of 50 queued flits per floute is supported" are antithetical to the basic design principles. However there may be various memory limits associated with particular uses of the entities that model a particular application. The DIAL system internally must have many protections that maintain its internal consistency at all times to prevent corruption of its state. However, unreliability of all components it models is allowed (and specifically designed for). The states of components are allowed to be inconsistent to some degree, such that a state like "blox went down" might arise at a random time. Typically in implementations, the "last known state" of a blox would be tracked, along with protocols to retrieve the most recent state and allow resetting or other manipulations of the state. Recent new technologies such as the Web and Java may be excellent environments for implementing aspects of the DIAL specification. Recent widespread interest and developments in intranets, workflow analysis, and reengineering may be very tangibly furthered through the introduction and use of DIAL systems. examples == 1. a DIAL system can be used to model the workflow of a company. Individual flits can be thought of as documents, and bloxes are the operations that transform the documents. The history mechanisms are identical to revision control. Floutes represent interactions or communication paths between people or departments. This is the primary "information assembly line" application of the DIAL concept. In this system, the "paperwork" cannot be lost because of the inherent properties of DIAL. In fact it is in these sitations that history, tracing, and "timeout" mechanisms are most valuable. The estimation feature gives an approximation of "how long will this take when submitted". 2. a DIAL system could reflect the internal state of packets on a network. Individual computers, routers, etc. are seen as bloxes, and messages are the flits, and floutes are the network routes. The DIAL tracing features are especially useful in this context. 3. a DIAL system could represent a large, complex software project. Individual bloxes are the components in the program. The versioning capabilities deal with the development pipeline. Regression testing and the process of moving to new versions is explicitly built into the system. 4. the DIAL system might represent data being sent over the World Wide Web. 5. the DIAL system could represent a distributed computing system in which the bloxes are spread out over the Internet (the floutes), and socket communication is used to transport flits. 6. In many debugging situations, "bad data" is detected without any knowledge of its history and complex measures are employed to try to deduce the prior processes that led to it. The history mechanism in DIAL allows a user to trace prior states of the flit and find the exact point or blox where the corruption occured. Also, the capability of putting a "rider" on a flit that detects when it is modified in some way is possible. 7. There is a natural correspondence between every computer language and the DIAL system. Subroutines or arithmetic operations are like bloxes, and parameters are passed in floutes. Variables are the contents of specific "floutes" at various points in processing.

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Re: [RANT] Giving Mind Control Drugs to Children
by Rick Smith 17 Dec '03

17 Dec '03

Tim writes about Ritalin: >I've been over visiting my friend to see some of this. The Ritalin-sodden >kid arrives like a zombie. When the Ritalin wears off, he's rambunctuous, >but all kids are. My friend Paul has had to discipline him a bit to keep >him from--as the psychobabbles would say--"acting out." This discipline >sets him straight, but it's not something his New Age "supermom" would ever >think of doing. Hence the kid throws temper tantrums, acts out, calls her >"You fucking asshole" (remember, he's only 8 or so), and so on. So she >cranks up his dose of Ritalin and he's zoned out for a while. Frankly, I >think telling the kid that if throws a tantrum he'll get punished for it is >a whole lot more normal--ever notice that a dog smacks her puppies when >they get out of line, or that a cat swats her kittens the same way? It >establishes the rules of the game. It sounds to me like the mom is abusing the drug -- Ritalin is tricky stuff and you can really mess up a kid by overdosing. That's child abuse, IMHO, not some benigh paddling. Alex, our 8 year old son, uses Ritalin. He doesn't need Ritalin to concentrate. He can get caught up in a building project for hours and create a masterpiece. He can focus so thoroughly you can't pry him loose. What Alex *can't* do is get comfortably through a day of grammar school. I sympathise -- I was the same way when I was that age. I had a tough time and I saw Alex having problems similar to mine. So I sic'ed the educational establishment on the problem. Alex ended up with a Ritalin prescription. At least for now. And it's been pretty effective. With Ritalin he finds it much easier to concentrate on drivel, an important skill to make it through school, or sports. The problem is that Ritalin isn't some useful, generically wholesome substance like milk or peanut butter -- you risk more than "acting out" if you're not incredibly careful. Sleep disorders at least. But I don't like the downside of doing nothing, so we're trying it out. I've *never* seen Alex zoned out on Ritalin. Rick.

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Re:Pseudo-DC-net Project
by mccoy＠communities.com 17 Dec '03

17 Dec '03

janke(a)unixg.ubc.ca writes: > I am working on a project to implement a variation of a DC-net to be run > over the Internet. I am posting this summary to find out if it overlaps > with projects others are working on; to see what members of the lists think > of the general ideas for the network I have in mind; and to see if anyone > is interested in helping me out. Short version: Your proposal will not work and is trivial for a TLA to break. Long version: There are two problems with this proposal, the star topology collapses the DC network into a two-party version of the DC-net protocol (in which collusion is trivial) and the shared PRNG allows _any_ participant to compromise a target member of the network (or evesdrop at the server and decode all traffic.) A simple example of such an attack would be for the TLA to register a host on the network and get the shared secret key for the PRNG. The TLA then taps in either to the server's internet connection or any point in the network which divides the client graph into two parts, the server and a single client on one side and the remaining clients on the other. The TLA then just XORs out the blinding data (which it knows because it is a member of the network) and it has all of the connections. Additionally, having a MAC is just plain silly, the objective is to hide who is sending and having a MAC defeats the entire purpose of the proposal. You have basically created a simple packet anonymizer, which is not bad in and of itself, but it is not even close to a true DC-net (at least I am assuming so, based upon the initial description.) You have not mentioned whether or not all traffic exits the network at the server, if this is the case you are better off having each client establish a secure link to the server, running a PRNG constantly that is mirrored by the server, and XORing all of their traffic in to this stream. The constant PRNG stream hides when the client is sending or receiving and the secure channel to the server discourages passive evesdropping. This does not defeat traffic analysis at the server, but then again neither does your proposal. Some other tips from someonw who has spent too much time thinking about DC-net implementations: Ignore collision detection, just use ALOHA or a similar protocol. Until you get up to serious bandwidth the computational cost is not worth the effort. Don't abandon the ring topology (this is where the DC-net gets its security.) Use multiple small (4-7 host) rings with overlap between the rings, think of each ring as a LAN and hosts which are on multiple rings as bridges/routers and you should get the picture... Bandwidth economy will always suck, you can use hash trees to get around a few of the problems but for the most part you have to accept the costs and work around them in other areas. You really, really need to read the 1987 Eurocrypt proceedings. jim

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Reno and G8
by jya＠pipeline.com 17 Dec '03

17 Dec '03

AG Janet Reno is meeting today with G-8 ministers in Paris to discuss anti-terrorism policies. Reports on those sessions from highly placed Euro subscribers would be appreciated. If needed, faxes of articles may be sent to 212-799-4003, anonymity assured. French, German or Spanish welcomed -- we've got translation software to garble them in English.

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