December 2003 - cypherpunks-legacy

Federal Control of Financial Transactions
by frissell＠panix.com 17 Dec '03

17 Dec '03

As regular readers will be aware, Tim May and I have been sparring with each other about the risks of various control strategies that the world's governments may deploy. I thought it might be helpful to make one of his fears concrete so that we can analyze it. I trust that I am not putting words in Tim's mouth. The major concern is the same one mentioned in the Book of Revelations: "REV 13:16 And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads: REV 13:17 And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name." So the Feds deploy a card (smart or dumb) that has to be used for most transactions and lets them track everything we do. Tourists are brought into the system through the use of temporary cards (or the machine-readable strip on their passports which already includes a space for a national ID number.) How is this most likely to come about? I consider force majeure to be unlikely. It would be rough to get Congress to impose a burden like this on businesses (who would have to completely wire themselves) in a formal vote. It is not necessary to do this in any case since they know they can't snag everyone into the system. They just want to capture most of the transaction data. If they can do it administratively without involving Congress in controversy, they will use that approach. Clipper and the Post Office agitprop on the US Card give us a possible scenario. The P.O., desperate to find a reason to exist as its core business drains away to the wires and private carriers, would like to become the primary digital signature authorizers for the U.S. It claims to be able to put millions of "US Cards" in the hands of happy shoppers within months of the go-ahead. (Assuming they use FedEx for the actual *shipments* of course). The recently attempted "Clipper maneuver" of game strategy (government preemption by standard setting rather than by direct application of force) shows us how the US Card system might be actually deployed. The government adopts the standard it likes and tries to make it the de facto standard by requiring it for most official business. An instant market is thereby created. No congressional action required. Similarly, the government might try to preempt the market for digital signature and commercial encryption technology by deciding to make anyone who wants to use a digital signature system in dealings with the government use the Post Office or some such agency as the signature authenticator. Thus bids, purchasing, benefits, and taxes could all require your "US Card" registered at your local post office. The government would then hope that commercial users who would need to use the government's system for tax filings anyway would also use it for its ordinary dealings with the public. Then if a health care bill drafting you into a "universal coverage" army is ever passed, the "US Card" also becomes the Health Security Card you will have to show to get a job in the US. Thus, all sorts of authentication transactions would pass through the powerful and efficient post office data network and the ex-countercultural/born-again control freaks Inside the Beltway could get their jollies tracking your employment and purchases. What's the big hole in this frightening scenario? Ask yourself one question. Why is the Post Office looking around for some useful work these days? Didn't they have a monopoly guaranteed by the Federal Government for more than 100 years? If they couldn't make a go of it with a pure coercive monopoly during a time of slower commercial activity, what makes them think that they can compete *without* a genuine coercive monopoly in a time of constant change. Governments have proved over and over again that they can go broke running "guaranteed" money spinners like state lotteries and such. They don't stand a chance in a marketplace that will break the hearts of the brightest people this planet has ever produced. What has recent history established? Governments are weaker. Why didn't the Amin mandate Clipper? No political ability to do so. Why are banks and telecoms being deregulated in nearly every country on earth (in spite of propaganda about "risks" and "public needs"? Why have exchange controls (a common feature of life a generation ago) become impossible almost everywhere on earth? Is it "free market ideology" that has triumphed or did the *reality* of markets rather than the *idea* of markets hit governments on the head. To those who romanticize the power of the State in the modern world I ask, why doesn't Clinton impose wage and price controls, exchange controls, tariffs, and a full-blown industrial policy? Why doesn't he nationalize the steel industry, guarantee jobs for all, confiscate all estates above $100,000, impose 95% income taxes on those making more than $40,000/year, and all of the other proposals that were popular earlier in this century? I doubt that he is restrained because of his deep commitment to human liberty. He doesn't do it because he can't. Markets wouldn't put up with it. His government would be destroyed (by capital flight.) In this connection, I invite everyone to read the excellent profile of Japan in last week's Economist. It discusses the current and growing Japanese commitment to deregulation and what is driving it. That issue is a keeper anyway because of an article on commerce on the Internet and (as has been mentioned before) the use of the word "anarcho-capitalism" in an article comparing Thailand and Singapore. Assuming that the government were to attempt to establish a Post Office mediated digital authentication system, there is no guarantee that it would work. Foreign users would presumably use foreign systems to authenticate their transactions. Some of these systems might be run by privatized foreign PTTs or by others. Note that since banks and credit agencies will still have to approve the transactions anyway (to make sure you've got the dough), they may decide to use other systems for signature authentication. It would not really cost them any more. Since information is cheap, setting up a system to use several authentication systems is almost as easy as setting up a system to use one. (Particularly since you have to do it anyway.) It is difficult to imagine the P.O. being able to compete in the cutthroat world of credit processing. Recall that even today, there are companies that pick up and deliver your mail to the P.O. to speed the process along. Similarly, expediters may interpose themselves between the customer and the P.O. to speed authentication in the even that the P.O. network is slow or inefficient (likely). Here again, Clipper gives us some hints as to how the attempted market cornering might work out in practice: The Admin is currently floating stories about perhaps withdrawing Clipper in favor of "wider discussions" with the industry. Clipper is already painfully obsolete and it isn't even shipping in quantity. Inefficient government monopolies create marvelous profit opportunities for markets to arbitrage the gap between cost and price. In a highly efficient networked world, it will be very difficult for governments to compete. DCF Why Pizza Hut should hire *me* as their spokesman: "Why does Pizza Hut oppose mandatory, employer-paid health insurance in the US even though we are forced to pay it in Japan and Germany? We support the principle of cultural diversity under which different societies experiment with different methods of social organization. Germany and Japan have chosen one road, we have chosen another. Pizza Hut would not voluntarily impose on our US customers the burden of the very high food costs that the agricultural policies of Germany and Japan impose on their citizens. Similarly, we would not choose to impose on our US employees the burden of bureaucratically designed employment contracts. Pizza Hut supports the right of our customers to enjoy the least expensive and best pizza on earth and the right of our employees to bargain with us collectively and individually concerning the conditions of their employment."

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PARTY: [2nd post] A Post Jovial Bash, July 23rd, Santa Cruz, CA.
by eric＠Synopsys.COM 17 Dec '03

17 Dec '03

[This is going to several lists with overlapping memberships. Apologies if you're recieving this more than once.] The bashing of Jupiter has begun, and in less than a week it will be over. That's certainly a cause for celebration, so you're invited to join me for a Post Jovial Bash. Where: A cozy geodesic dome nestled in the Santa Cruz mountains. Directions are included below. When: Saturday, July 23, 1994. The party begins at noon. Crash space is available if you wish to stay until Sunday. What to bring: Food and/or drink to share and enjoy. I'd like to encourage people to bring healthier items: low-fat and/or vegetarian food, juices, etc... but nothing will be turned away. A grill will be available, and I will be providing some food and drinks. Suggestions and contributions are welcome. Musical instruments. A towel (you do know where it is, don't you?) for enjoying the hot tub. It will be clothing optional, but probably not used until it cools off in the evening. Bedding if you suspect you might want to spend the night. And of course, bring interesting people, ideas, and things. Note to cat allergy sufferers (like me): 6 cats live in the house. Be prepared. To print a map and directions, snip off the file below and send it to any PostScript(tm) printer. If you haven't got one, you'll have to make do without the map. Just read the text at the top of the file for directions. Be seeing you -- -eric messick PS: PostScript is a registered trademark of Adobe Systems Incorporated. ------>8------>8------>8------>8------>8------>8------>8------>8------>8 %!ps % Directions to KT & Eric's dome % % KT & Eric % 15139 Old Ranch Rd % Los Gatos CA 95030 8506 % +1 408 353 4751 % % From San Jose, take Highway 17 South from Highway 280 for 15 miles. % From Santa Cruz, take Highway 17 North from Highway 1 for 12.5 miles. % Exit Highway 17 at Summit Road (the only bridge over Highway 17 in % the mountains), and head west. % 0.5 miles west of 17, turn left from Summit Road onto Hutchinson Road. % 0.2 miles from Summit, just after Riva Ridge Road on the left and a long % group of mailboxes on the right, turn right from Hutchinson onto % Old Ranch Road. % A short distance down Old Ranch there is a three-way fork. The left % branch is a small driveway; the center branch is Old Ranch Road which % continues around a curve to the left (a sign points to the left to % indicate this); and the right branch leads to our house and three % others. Our address (15139) is on the top of a sign to the right. % Turn onto the rightmost fork, down a steep grade. % Our geodesic dome is 0.4 miles from Hutchinson Road down the rightmost % fork of Old Ranch Road. /fg { 0 setgray } def /bg { 1 setgray } def /r { moveto currentpoint } def /a { rmoveto pop pop currentpoint } def /ah { pop pop currentpoint } def /rc { rcurveto } def /lab { % x y alpha (str) gsave 4 2 roll rmoveto exch rotate show grestore } def /nl { show 7 sub r } def bg clippath fill 4.25 72 mul 5.5 72 mul translate 90 rotate 2 2 scale /Helvetica findfont 5 scalefont setfont 0 0 moveto currentpoint 70 -100 a currentpoint % North arrow 50 30 a fg 3 setlinewidth 0 60 rlineto ah stroke r 0 -10 1 -15 5 -20 rc stroke r gsave -5 5 rmoveto /Times-Bold findfont 13 scalefont setfont (N) show grestore pop pop r -12 20 -90 (to Santa Cruz -->) lab -25 210 -65 (<-- to San Jose) lab 11 setlinewidth fg 2 120 -10 170 -30 200 rc stroke r % 17 outer lines 7 setlinewidth bg 2 120 -10 170 -30 200 rc stroke r % 17 interior 1 setlinewidth fg 2 120 -10 170 -30 200 rc stroke r % 17 center 1.25 100 a 10 -40 270 (Highway 17) lab 2 setlinewidth -2.5 27 rmoveto fg 2 -7 5 -9 14.5 4.7 rc stroke r % summit to 17n -8.2 0 rmoveto fg -2.5 20 -10.5 30 -20.5 50 rc stroke r % summit to 17s -12.75 35 rmoveto fg 2 -15 -4 -8 -13.3 10 rc stroke r % 17s to summit 1 setlinewidth -3.2 49 rmoveto % bridge fingers fg 5 5 rlineto stroke r -3.2 49 rmoveto fg .85 -7 rlineto stroke r -18.5 52 rmoveto fg -3 6 rlineto stroke r -19 52 rmoveto fg -2 -6 rlineto stroke r -1 48 rmoveto % bridge border 9 setlinewidth fg -8 3 -13 5 -20 4 rc stroke r -1 48 rmoveto % bridge interior 7 setlinewidth bg -8 3 -13 5 -20 4 rc stroke r 2 setlinewidth .5 0 rmoveto fg 0 20 9.5 30 19.5 40 rc ah stroke r % 17n to summit currentpoint fg 10 10 25 15 40 10 rc stroke r % summit e 33 15 -15 (Summit Rd) lab 25 11.5 rmoveto fg 10 10 10 20 5 40 rc stroke r % mt charlie e 30 70 -80 (Mt Charlie Rd) lab 5 15 25 (Phone) lab 0 5 25 (Parking lot) lab pop pop r fg -20 10 -40 15 -48 10 rc ah stroke r % across bridge fg -16 -10 10 -35 -3 -43 rc ah stroke r fg 5 -10 0 -20 5 -30 rc stroke r % mt charlie w 5 -5 -80 (Mt Charlie Rd) lab fg -13 -8 -20 20 -30 15 rc ah stroke r fg -10 -5 -30 -20 -55 -20 rc ah stroke r fg 5 -10 0 -20 5 -30 rc stroke r % stagecoach 5 -5 280 (Stagecoach Rd) lab fg -25 0 -10 -20 -15 -25 rc ah stroke r fg -5 -5 -30 0 -40 0 rc stroke r % summit continues... -45 5 -5 (Summit Rd) lab fg 5 -5 0 -20 0 -30 rc ah stroke r % hutchinson 5 25 -90 (Hutchinson Rd) lab % side road could go here fg 0 -10 3 -10 5 -17 rc ah stroke r fg 5 -5 10 -8 20 -8 rc stroke r % riva ridge 15 -5 0 (Riva Ridge Rd) lab fg 1 -3 1 -4 2 -7 rc ah stroke r fg 1 -3 5 -5 10 -7 rc stroke r % hutchinson continues... 3 -12 -20 (Hutchinson Rd) lab 1.5 setlinewidth fg -5 -5 -10 8 -15 3 rc ah stroke r % old ranch fg -3 -3 0 -10 5 -15 rc stroke r % old ranch continues... -8 -9 -55 (Old Ranch Rd) lab 1 setlinewidth fg 2 1 rmoveto -1 -2 1 -4 5 -7 rc stroke r % left fork driveway fg -5 5 -15 15 -20 12 rc ah stroke r % our portion of old ranch fg -5 -3 -15 -15 -25 -10 rc ah stroke r fg -10 5 -15 5 -20 0 rc ah stroke r fg -5 -5 -10 -5 -20 0 rc stroke r % our portion continues... fg 5 -5 rlineto ah stroke r % our driveway fg 7 2 rmoveto currentpoint newpath 3 0 360 arc stroke r /Helvetica-Bold findfont 5 scalefont setfont -15 -10 0 (KT & Eric) lab -15 -15 0 (15139 Old Ranch Rd) lab -15 -20 0 (Los Gatos CA 95030 8506) lab -15 -25 0 (+1 408 353 4751) lab -155 115 moveto ah /Times-Roman findfont 6 scalefont setfont (From San Jose, take Highway 17 South from Highway 280 for 15 miles.) nl (From Santa Cruz, take Highway 17 North from Highway 1 for 12.5 miles.) nl (Exit Highway 17 at Summit Road $the only bridge over Highway 17 in) nl ( the mountains$, and head west.) nl (0.5 miles west of 17, turn left from Summit Road onto Hutchinson Road.) nl (0.2 miles from Summit, just after Riva Ridge Road on the left and a long group) nl ( of mailboxes on the right, turn right from Hutchinson onto Old Ranch Road.) nl (A short distance down Old Ranch there is a three-way fork. The left branch is a) nl ( small driveway; the center branch is Old Ranch Road which continues around a) nl ( curve to the left $a sign points to the left to indicate this$; and the right branch) nl ( leads to our house and three others. Our address $15139$ is on the top of a) nl ( sign to the right. Turn onto the rightmost fork, down a steep grade.) nl (Our geodesic dome is 0.4 miles from Hutchinson Road down the rightmost) nl ( fork of Old Ranch Road.) nl -80 128 moveto ah /Times-Bold findfont 12 scalefont setfont (Directions to KT & Eric's dome) nl pop pop showpage

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Re: Encrypting fax machine
by Ben.Goren＠asu.edu 17 Dec '03

17 Dec '03

At 6:07 AM 7/18/94, John Young wrote: >[. . .] >We use an encryption algorithm called seeded pseudo-random >number generator, Mr. Varga said. The company chose that >algorithm because it is in the public domain, he added. *Groan* One would think that anybody who would go to the expense of designing an encrypting FAX machine could at least afford to read the introduction to any beginning crypto book. Heck, I bet it's even the generator on page 46 of K&R's second edition C book. b& -- Ben.Goren(a)asu.edu, Arizona State University School of Music net.proselytizing (write for info): Protect your privacy; oppose Clipper. Voice concern over proposed Internet pricing schemes. Stamp out spamming. Finger ben(a)tux.music.asu.edu for PGP 2.3a public key.

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y'all gotta see True Lies
by jdblair＠nextsrv.cas.muohio.EDU 17 Dec '03

17 Dec '03

Hey y'all, check it out! The cypherpunks better go to the movies! I just got back from True Lies, the latest Arnie flick. I recommend y'all go see it. Hollywood's managed to push the collective american button yet another time, ladies and gentlemen. Where's the "Dr. Strangelove" of the 90's when we need it? I'll make a short list: 1) Passionate Arabs driven to find there revenge through stolen Soviet nuclear weapons. 2) A "blanket order" to a vague, unknown government agency to wire tap anything they feel like. 3) Fear that, because there are no customs or controls regulating traffic between the Florida Keys and the mainland, the terrorists will be able to drive anywhere with their fancy nuclear weapon. 4) After summoning the skill to purchase a nuclear weapon, smuggle it into the United States undetected (except for the suspicions of our amazing Arnie and his crack team), and detonate one of them in the Keys, still unable to work a video camera with reliability (oh, those crazy wacko arabs! Oh the magic of Hollywood!) 5) Of course, every hacker in the audience noticed that the rich multinational zillionaire is unable to choose encryption secure enough to fend off an attack on minutes in length using computer equipment in a van! What was he using to hide his records? Enigma? 6) Oh yeah, the women are unable to do anything except talk on the phone, get into catfights, give men blowjobs, and kill people by accident. The only female villain is clever, but the screenplay is sure to point out that she has not principle other than the dollar (or yen, pound, mark, etc). This is a very male film, even without getting into that old 60's cliche about missiles being penis extensions. 7) Luckily, amid all the casual death in the name of national security and the american way, we have Arnie pointing out that "he only kills bad people." Reminds me of the time I was at the Space and Rocket Center in Huntsville, right after the Gulf War. They had a patriot missile on display, along with the wreckage of a "busted scud." A mother pointed to the missile, saying to her son, "Look, its the patriotic missile." I am not making this up. Y'all better get crackin', you clever cypherpunks. We sit here and chat about the National ID card, and argue about the best way to not pay our taxes (should I lease my car from a front, or buy it from the Mafia? What if I get a speeding ticket?). Meanwhile, the REAL MEDIA, the MOVIES, the TV, and all the other DRUGS most of America uses to ignore their surroundings are giving people the armor to fend off all the reason in the world we will ever cook up. "You can see, as the movie 'True Lies' showed, its relatively easy for a group of Arab terrorists to land in America and cruise up the coast with a nuclear weapon! Just think how easy it is for some Joe to walk on in with a kilo taped to his belly, and feed it to your kids! Worse, a whole family of Mexicans could sneak in and collect YOUR welfare check! (pregnant mother giving birth the moment she steps on American soil!" Choose whatever villain you wish for the delivery. The lefties can imagine Ronnie Boy calming us with his liquid voice. Those of other persuasions can choose Billary Klinton, promising us health and benefits. Maybe I'll imagine that guy my parents told me about... I think his name was Mixon or something like that. I doubt it'll matter who's holding the wheel. I think the car's driving itself. If anyone has a good monkeywrench, send it my way. -john. -------------------------------------------------------------------------- John Blair: <jdblair(a)nextsrv.cas.muohio.edu> voice: (513) 529-2961 http://phoenix.aps.muohio.edu/users/jdblair/home.html KILL YOUR Finger me for PGP key. TELEVISION Too much proximity to folly tends to make it seem normal. --Edward Abbey

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Re: JUST GO AWAY Sue D nym!
by snyderra＠dunx1.ocs.drexel.edu 17 Dec '03

17 Dec '03

At 2:14 PM 7/18/94, kelly(a)netcom.com wrote: > Hey detweiler... I am not as gentle as perry is... just go away... >you DONT have any votes here... p.s. I WIll be notifying netcom management >again of your activities... When I joined the list, I received a note describing Detweiler, and asking me not to react to said person. This seems like good advice. I have placed "Sue" in my mail filtering program. I suggest that those who feel that "Sue D. Nym" is Detweiler do the same, and ignore the person. If it is Detweiler, he's having his desired effect. Bob -- Bob Snyder N2KGO MIME, RIPEM mail accepted snyderra(a)dunx1.ocs.drexel.edu finger for RIPEM public key When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

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Re: The Detweiler Files on FTP
by rishab＠dxm.ernet.in 17 Dec '03

17 Dec '03

rah(a)shipwright.com (Robert Hettinga): > On the other hand, how old is this guy? 12? I mean what do we really know > about him? Do these archives have anything on him besides his spam and the > resultant fusilades? Has anyone actually met him? Not that I'd like to, I > guess... He's obviously intelligent and rather older than 12. The archives have someone's well-researched trace of his activities, Tim May's (lengthy) biography of LD, and some of his sane posts -- such as a correspondence with Diffie. ----------------------------------------------------------------------------- Rishab Aiyer Ghosh "Clean the air! clean the sky! wash the wind! rishab(a)dxm.ernet.in take stone from stone and wash them..." Voice/Fax/Data +91 11 6853410 Voicemail +91 11 3760335 H 34C Saket, New Delhi 110017, INDIA

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How to legally circumvent the PGP 2.6 "legal kludge"!
by Paul Elliott 17 Dec '03

17 Dec '03

How to legally circumvent the PGP 2.6 Legal Kludge. According to the pgpdoc2.txt that comes with PGP 2.6: >PGP version 2.6 can read anything produced by versions 2.3, 2.3a, 2.4, >or 2.5. However, because of a negotiated agreement between MIT and >RSA Data Security, PGP 2.6 will change its behavior slightly on 1 >September 1994, triggered by a built-in software timer. On that date, >version 2.6 will start producing a new and slightly different data >format for messages, signatures and keys. PGP 2.6 will still be able >to read and process messages, signatures, and keys produced under the >old format, but it will generate the new format. This incompatible >change is intended to discourage people from continuing to use the >older (2.3a and earlier) versions of PGP, which Public Key Partners >contends infringes its RSA patent (see the section on Legal Issues). This is the "legal kludge". However there is an undocumented PGP parameter in PGP 2.6 which appears to be intended to allow the PGP user to disable this "feature". This parameter may only be specified on the command line using the "+" syntax. It is thought that it was intended that one could disable this feature using a command like the following: pgp +legal_kludge=off -e file However this does not work. In the source file config.c we find: case LEGAL_KLUDGE: legal_kludge = value; break; Since legal_kludge is a Boolean variable, the specified value "=off" is in the variable "flag". Value usually has the wrong number, since it is not set for Boolean values. Thus due to what appears to be a bug, we can not use the "legal_kludge" parameter to disable the kludge. Perhaps the bug is not really a bug at all, but a feature. After all it does limit the interpretability of pgp 2.6 with earlier versions. We can not fix this bug without violating MIT's licensing requirements. >2. Software included in this compilation includes a feature that >causes the format of messages generated by it to change on September >1, 1994. Modification to this software to disable this feature is not >authorized and will make this license, and the license in the >underlying software, null and void. If we were hell-bent to frustrate RSA and MIT, we would simply use pgp26ui and not tell them about it rather than hack their sacred kludge. It would seem to be an impasse. Or is it? Note that value is declared statically: >static int value; Every time a numeric parameter is parsed the variable value is used to hold the number. So all we have to do is specify a numeric parameter of zero before we specifying "legal_kludge"! We can then set that parameter back to the desired value if zero is not desired. That is the following works! >pgp +cert_depth=0 +legal_kludge=off +cert_depth=4 -e file The above assumes that we wish to use 4 as the value of cert_depth. We set cert_depth to zero only to get the value of "value" to 0. The the legal_kludge parameter will set the value of "legal_kludge" to be =value=0, then we set cert_depth to the real desired value. This trick is legal, because we have not modified pgp 2.6 in any way. We are simply exploiting a bug or feature in the way PGP 2.6 is written. This kludge may seem to be too kludgy! It is asking a lot to ask users to type such a thing! But is this really a problem? Most users do not invoke PGP directly. They usually invoke PGP thru a mail program or some other shell program. These shell programs can be easily modified to do the right thing. In the worst case, people could define a shell alias to invoke pgp with the incantation! This discovery will allow people who must use PGP 2.6 to communicate with people with earlier versions of PGP! ------------------------------------------------------------------------------ Paul Elliott Telephone: 1-713-781-4543 Paul.Elliott(a)hrnowl.lonestar.org Address: 3987 South Gessner #224 Houston Texas 77063 --

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RE: Federal Control of Financial Transactions
by Blanc Weber 17 Dec '03

17 Dec '03

Some comments on Duncan's post: All of the arguments which he proposes against reasons why the government can't succeed are true and accurate; however, it is one of those things where "you know and I know, but *they* don't know"...... The examples which you relate of government failures from inefficiency, etc. have been proven time and again in history, but in that case why does history keep repeating itself, in slightly different variations. "......why doesn't Clinton impose wage and price controls, exchange controls, tariffs, and a full-blown industrial policy?" If he can succeed in implementing the Health Plan, and if the National ID were accepted, that would probably next on his agenda (if he were to be re-elected [2 more years]). One saving grace from all the discussions which are going on of the above projects is that they presently are just discussions, and if they could just be kept discussing these things, none of them will ever be accomplished. By the time the discussions are finished, everyone will have version 10.x of every computer app and all companies will be "virtual". Blanc

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Re: Why triple encryption instead of split+encrypt?
by John Douceur 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- >From: <solman(a)MIT.EDU> >Date: Monday, July 18, 1994 4:18PM >Clearly, if you have access to P0, P1; C0 and C1 this attack crushes the >algorithm. In most books I've seen, it is assumed that you do not have >access to this. The assumptions about the information available to the cryptanalyst vary with the type of attack. The essence of a known-plaintext attack is that both plaintext and cyphertext of several messages are known, and the task is to deduce the key. This is more practical than it may sound, since there may be (for example) header information that has small or no variability among messages. >Nonetheless, your cryptanalytic algorithm makes clear an additional >constraints that must be placed on the system which I had not realized: >From the algorithm, the plaintext, and the cypher text, in must not be >possible to reconstruct both the plaintext, and the cyphertext for either >half of the message. >To that end I would suggest the improvement of making the splitting >operation dependent on the keys. For that matter, one could have a third key which is used by the splitting algorithm. If one chooses to make this splitting key a function of the two DES keys, then this approach reduces to your suggestion, at the expense of a smaller keyspace. It could be said that, in the code fragment of my previous message, the splitting key is fixed at 0x55555555. So now the meet-in-the-middle attack regains its earlier applicability: A known-plaintext attack would encrypt P with the splitter, decrypt C0 with DES, and attempt to meet in the middle to discover key K0; similarly, decrypting with C1 to get K1. If you can design a splitter that is as cryptographically secure as DES (good luck), then the resulting algorithm is as secure as double DES. Actually, the computational complexity of a cryptanalysis would be somewhere between one and two times that of double DES, since it requires one encryption analysis and two decryption analyses. In your previous message, you commented: >I have a hunch that if I'm wrong, its because the time required to do secure >non-redundant secret splitting is as large as the time I'm saving. If your secret-splitting algorithm is as secure as DES, then it probably runs as slowly as DES does, making your hunch correct. However, even if this were not the case, the security of this scheme is significantly less than that of triple DES. JD -----BEGIN PGP SIGNATURE----- Version: 2.6 iQCVAgUBLisjcEGHwsdH+oN9AQHwDgQAualDZ4kcq15Cs/oIufau4f23x11gVmEY nAkWt7teczUa+ZUHIRrsY1x3D6FDgzQLdBeajMpz3W8XHzO9HjAykbx3Rg8eTeQf ZjGtysnNhSqJwtQLypGhZV+kSv8n4UY5lYkhGHVhTbnn/2ynyjKmqZMkmoN66Klt GcbayT4Jhzw= =qfay -----END PGP SIGNATURE-----

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Recent references to Crypto in the media...
by Jim choate 17 Dec '03

17 Dec '03

Hi all, Just a note to alert those interested that the latest issue of PC Magazine has two articles about crypto. One is about public key and DES and the general currents. The second is in reference to WinCrypt. Both articles are very general and do not delve into technical discussion. Take care.

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