December 2003 - cypherpunks-legacy

Anonymous Remailing Revisited
by Arthur Chandler 17 Dec '03

17 Dec '03

This is from RISKS Digest: ******************* Quoting from the Feb. 24 News-Gazette of Champaign-Urbana, Illinois: "UI student arrested for e-mail threat to Clinton" URBANA -- A University of Illinois student has been arrested for threatening the life of President Clinton, U.S. Attorney Frances Hulin announced today. Christopher James Reincke, 18, of Townsend Hall, Urbana, allegedly sent an electronic mail message to the White House on Dec. 4 threatening Clinton, Hulin stated in a press release. The message read: "I am curious, Bill, how would you feel about being the first president to be killed on the same day as his wife ... It would be best, I think, to not continue with your immediate plans. Perhaps a vacation. You will die soon. You can run, but you cannot hide." The message was signed "Overlord" and purported to be from "Allmighty(a)Never.Gonna.Catch.Me." Reincke appeared before U.S. District Judge Harold A. Baker in Danville today and was released on his own recognizance. Hulin said the charge resulted from an investigation by the Secret Service and the UI police. Investigators determined the message originated at the UI, and a computer trace identified Reincke as the apparent author, Hulin said. While being questioned by agents, Reincke admitted he had sent the message, according to the press release. ]

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Re: ditz in office
by joshua geller 17 Dec '03

17 Dec '03

blanc writes (in response to mike godwin): >Why do you think that there would have been no difference? Do you not >belive that Andre/Nancy (or any other Libertarian types) would *not* >have taken a different stance towards: take your pick, but relevant to >cypherpunks, about Clipper & the other surveillance plans? they didn't have a chance of winning though. both republicans and democrats screw you, just in slightly different ways. it was time to give the one orifice a rest. josh

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Denning
by rcain＠netcom.com 17 Dec '03

17 Dec '03

Ron Rivest sez: > > Hi Dorothy -- Fine till here. :-) > > Thanks for sending me a copy of your editorial. But I find the > reasoning you present misleading and unpersuasive. I found it subtle and persuasive. > > First, you argue that the clipper chip will be a useful law > enforcement tool. Given the small number of currently authorized > wiretaps per year (under 1000) and the ease of using alternative > encryption technology or superencryption, it seems plausible to me > that law enforcement could expect at most ten "successful" clipper > wiretaps per year. This is a pretty marginal basis for claiming that > clipper will "block crime". We agree here. Unless the use of other, harder methods are explicitly denied Clipper makes no sense at all. It is too easy to compete with. Just come up with something cheaper that doesn't require escrow and sell the thing. Poof Clipper. Clipper is alive I think for other reasons. The obvious conjecture is the ratio of unauthorized to authorized wiretaps each year. It is not the authorized ones that has the various intelligence gathering orgainizations worried. At best it can be a conjecture but I am certainly of the belief that if LE or NS wanted to find a reason to nail one for something, his phone, tap authorized or not, would lead them right to it. Thus I think that wiretaps are far more prevalent than we can know because it is too easy to use them in a "transparent way". This is one reason why, I believe, that we can't be told the importance of this, as Dr. Denning states. That would reveal it's usage as well as its effectiveness. A lot of people would not like the numbers. One reason for the Clipper is to give the public an alernative it could live with which would not allow what is perceived as excess if run properly but still be available to protect them in warented cases. > > Second, you seem to believe that anything that will "block crime" must > therefore be a "good thing" and should therefore be adopted. This is > not true, even if it is not subject to government abuse. For example, > a system that could turn any telephone (even when on-hook) into an > authorized listening microphone might help law enforcement, but would > be unacceptable to almost all Americans. This analogy has power because the whole question now really becomes what level of intrusion is acceptable. Only a judgement call here based on personal politics is possible, I am afraid. > As another example, tatooing > a person's social security number on his or her buttocks might help > law enforcement, but would also be objectionable. Aw, C'mon, out of the ballpark and right of right field. :-) > Or, you could > require all citizens to wear a bracelet that could be remotely queried > (electronically, and only when authorized) to return the location of > that citizen. This, as above, is a level of intrusion decision. > There are all kinds of wonderfully stupid things one > could do with modern technology that could "help" law enforcement. > But merely being of assistance to law enforcement doesn't make a > proposal a good thing; many such ideas are objectionable and > unacceptable because of the unreasonably large cost/benefit ratio > (real or psychological cost). Hmmm, this one has me paused. Back again. Ok, what is the cost benefit ratio? I want to be pragmatic about this and hopefully not ideological but it will probably sound simply paranoid. The benefit is that we citizens of the world now gain the abiblity to be in the same room together, for any intent or purpose, wherever we might be in the world. The cost of this ability remains to be seen but Dr. Denning believes it to be very high. It is certainly revolutionary in every sense of the word. :-) The benefit to business is obvious, yawn, and to illicit lovers, hmmm, but to the average person, personal security could be used as an argument for giving up personal privacy so long as it was sufficiently hard to invade that privacy (which it obviously isn't now.) > The clipper proposal, in > my opinion, is of exactly this nature. Perhaps, but for another reason. It is now just too plain easy to make an alternative box with real security which is capable of Clipper piggyback that it makes any sense to have Clipper at all unless the other shoe drops which all babblings so far say won't. Unless other forms are outlawed, Clipper has a decidedly short lifetime. If other forms are outlawed, only outlaws will have them, and have them they will. If the Blue Boxes of the '60s and '70's could be blue marketed for fair sums, imagine the black market in easy to use Black Boxes. > > Third, you seem unnecessarily polly-annish about our government and the > potential for abuse. The clipper proposal places all trust for its > management within the executive branch; a corrupt president could > direct that it be used for inappropriate purposes. Agreed. A better escrow method involving at least two of the branches would be preferable. Pretty hard to involve congress so that leaves the judiciary and the executive. Something could be made to work here I think. > The unspecified > nature of many of the associated procedures leaves much room to > speculate that there are "holes" that could be exploited by government > officials to abuse the rights of American citizens. Even if the > proposal were modified to split the trust among the various branches > of government, one might still reasonably worry about possible abuse. Yes, but it sure helps. If the judiciary holds one half and only will combine it with the other if *it* makes the decision to allow the tap then we would seem to have a system that works the way that many want. Abuse is possible of any system that man creates and this one is not immune by any means but it could be made very difficult. > Merely because you've met the current set of representatives of > various agencies, and feel you can trust them, doesn't mean that such > trust can be warranted in their successors. One should build in > institutional checks and balances that overcome occasional moral > lapses in one or more office holders. My hope would be that the judiciary act as the throtle or governer of government that it was designed to be. Granted one can argue at length as to how well it has remained detached and fulfilled that role but it is still the best alternative. > > Fourth, your discussion of "searching your home and seizing your > papers" is misleading. You seem to imply that because law enforcement > can be issued a warrant to search your home, that we should adopt > clipper. Yet this analogy only makes sense if individuals were > required to deposit copies of their front door keys with the > government. I can build any kind of house I wish (out of steel, for > example), and put any kind of locks on it, and wire up any kind of > intrusion detectors on it, etc. The government, armed with a search > warrant, is not guaranteed an "easy entry" into my home at all. The > appropriate analogical conclusion is that individuals should be able > to use any kind of encryption they want, and the government should be > allowed (when authorized, of course) to try and break their > encryption. I have absolutely no argument with this in theory. Ron, it is a very good defense but for the difference in media. To ignore the difference between the medium of a door and the medium of a communications channel is naive. If you merely consider them as two forms of communication your analogy breaks immediately. > > Finally, you argue (elsewhere, not in this editorial) that the decision > rests in part on "classified" information. Such an argument only makes > sense if there is a specific law-enforcement situation that makes such > classified information timely and relevant. (E.g., if there was a > current investigation as to whether the Department of the Treasury had > been infiltrated by organized crime.) The use of "classified information" > is otherwise generally inappropriate in discussing communications policy > that will last over decades. I totally disagree. To me it is self obvious that if there were problems that just our knowing would make worse it would be a good idea that we not know about them. National security with the vast dollars spent on the problem understands. I think this resistance from Dr. Denning is a function of her gnowing. I know how unpopular it has become to consider the U.S. government as anything but idiots but I am not so sure about that. You here admit to being of the "punk" thinking. What if this is an issue that is beyond the ability of a punk to really know anything about at all? > > This hardly covers all of the relevant issues, but it covers the > points that came immediately to mind in reading your editorial... I look forward to more. Please include cypherpunks on your Cc: list. Yeah, you are are guaranteed a volume of bullshit but there are some smart people there too. > > P.S. Feel free to pass along, quote, or otherwise re-distribute this... You didn't mention respond. I hope that is ok. :-) Peace, Bob -- Bob Cain rcain(a)netcom.com 408-354-8021 "I used to be different. But now I'm the same." --------------PGP 1.0 or 2.0 public key available on request.------------------

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Re: standard for steganography?
by norm＠netcom.com 17 Dec '03

17 Dec '03

Has anyone done statistical studies of low bits of pixels or sound samples? I suspect that they are often far from random. A flat 50% distribution in the low bits might standout like a sore thumb. I can imagine the the low bit can be distributed dependently on such things as the next to low bits or 60 cycle power at the recorder. Some AD converters are known to produce 60% ones or some such. Like mechanical typewriters, AD systems probably have there own idiosyncrasies. Given a flat stream of cipher data, there are techniques to reversably introduce such variations to mimic the biases of real AD converters without much data expansion. It is my wild guess and conjecture that with such statistical variation built in there would be no effective statistical test for a given file containing hidden messages.

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Re: standard for stefonography?
by jdblair＠nextsrv.cas.muohio.EDU 17 Dec '03

17 Dec '03

Correct me if I'm wrong, but the "Standard Stego" package that has been discussed could operate like the "stealth ocean" ideas that have been discussed. Some sort of hash function defines "random-like" bits to be accessed in a consecutive form. These bits can be located in a hard drive full of digitized noise, a jpeg or gif file, a CD, or any other large chunk of data. The access mechanism can be standardized. Without the key string, you don't know which bits are random and which are data. -john.

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On meetings
by hughes＠ah.com 17 Dec '03

17 Dec '03

Tim asked me to clarify the bit about emergency meetings. I thought he was consider moving the meeting time, among other things. He was not. I mistook his article. Sorry for the misunderstanding. Eric

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Problems w/ Clipper
by Anthony D Ortenzi 17 Dec '03

17 Dec '03

I think that in order to cut down on the amount of bickering of the problems that we have with Clipper, it would be best to sum up a bit. 1) Most of us are concerned not with our own privacy if other forms of encryption are not banned. Many people on this list use PGP, and almost all of the rest know damned well that they could if they thought that they had to keep something secret. (not plugging PGP, per se, but using it as an example because of its relatively large usage among 'punks) In other words, our problems tend to lie in the fact that the people of the United States are as a rule, well, not too concerned about the privacy of their own e-mail, and don't see this as a step towards what is in the book 1984. 2) Collectively, we seem to agree that letting the Government into our lives in such a way as Clipper provides is not necessarily all that evil, but if we give in a little, they will try to take it all. Am I right? (trying to center the discussion) Anthony Ortenzi ao27(a)andrew.cmu.edu

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Re: Anonymous Remailers Revisited
by mpd＠netcom.com 17 Dec '03

17 Dec '03

Arthur Chandler <arthurc(a)crl.com> writes: > Investigators determined the message originated at the UI, and a > computer trace identified Reincke as the apparent author, Hulin > said. Obviously Mr. Reincke did not encrypt his message with PGP and chain it through the correct number of anonynous remailers. :) -- Mike Duvos $ PGP 2.3a Public Key available $ mpd(a)netcom.com $ via Finger. $

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*Time Magazine* article on Clipper
by jimn8＠netcom.com 17 Dec '03

17 Dec '03

(Sorry for the "from" and "to" names; I'm using elm and it just doesn't format the headers in a way that the Cypherpunks list software's happy with) America Online goofed, and let a preliminary description of this week's Time magazine remain online after Time pulled an article on Clipper at the last minute. I've got a screen snapshot of the welcome screen containing the promo text, as well as email from Tom Mandel, who maintains the Time Online information. He says it was pulled due to late breaking news. So, if Time puts out an article favorable to Clipper, and distracting the public's attention from mandated key escrow, it might make sense to do a little investigative journalism of our own. Not that I'd accuse Time of knuckling under to Administration pressure to pull the article, or making revisions based on NSA "advice." Are EFF and CPSR doing everything possible to get media attention? Can't the EFF hold a press conference and hand out a "Big Brother" award to whichever congresscritter has done the most to hurt the cause of privacy? Any of the sponsors of the FBI Wiretap bill would do. A little heavy adverse publicity might give pause to other critters, at least the ones up for re-election anyway. - Jim Nitchals

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Re: standard for steganography?
by norm＠netcom.com 17 Dec '03

17 Dec '03

At 0:56 3/1/94 -0500, Sergey Goldgaber wrote: >On Mon, 28 Feb 1994, Norman Hardy wrote: > >> Has anyone done statistical studies of low bits of pixels or sound samples? >> I suspect that they are often far from random. A flat 50% distribution in >> the low bits might standout like a sore thumb. I can imagine the the low ... >Yes, pure white noise would be anamalous. I have suggested that one use >a Mimic function with a "garbage grammar". Implemented correctly, it should >withstand statistical analysis. > >What is an AD converter? And what are the techniques you speak of that >mimic those AD converters? 'AD converter' = 'Analog to Digital converter'. Here are three schemes each with flaws: Consider an alphabet of 10 bit characters with a probability distribution such that each bit has an expected value of .6 (instead of the normal .5). The character 000000000 has a probability of .4^10 = .000105 and p(1111111111) = .6^10 = .006046. Do a Huffman encoding on this alphabet. 000000000 codes as 13 bits and 1111111111 codes as 7 bits. Take the cipher stream and execute the Huffman decode(!) operation on the cipher stream. Out comes a sequence of 10 bit bytes with 60% ones. To retrieve the original cipher stream execute the normal Huffman coding algorithm and get the original stream. The flaw here is that Huffman assigns some probability to each of the 10 bit characters which is 2^-7, 2^-8, ... 2^-13. The intermediate probabilities are not represented. This would show up without too much data. Another scheme is called 'arithmetic coding'. It avoids the above probability quantization but is tricky to program. I can't find a reference to it just now but it should appear in any modern book in information theory. Unlike Huffman it does not code each character into a definite number of bits but codes a sequence of several characters into a 'real number'. Adapting this to numbers that real computers can use is tricky. Again you feed the flat cipher stream into the decoding end of the algorithm and get biased bits. The above two schemes are information efficient. With a 60% bias you get 97% efficiency. If you are willing to settle for 80% efficiency you can merely establish a RNG synchronized at sender and receiver that sends a bit from the cipher stream with probability .8 and sends a one with probability .2.

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The answer.
by Jeremy Cooper 17 Dec '03

17 Dec '03

I think I have found the way to end all our problems: ESP. Consider a secure public-key ESP connection from your head to mine. It's perfect. I think that we should work on developing this right away! _ . _ ___ _ . _ ===-|)/\\/|V|/\/\ (_)/_\|_|\_/(_)/_\|_| Stop by for an excursion into the-=== ===-|)||| | |\/\/ mud.crl.com 8888 (_) Virtual Bay Area! -===

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Re: DES Question
by smb＠research.att.com 17 Dec '03

17 Dec '03

Mainly to sabotage the performance of DES software implementations. Even back then the government knew it was much easier to control the dissemination of hardware than software. Are you sure? I got the distinct impression it was related to serial/parallel conversions on the chips of the time.

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Re: ditz in office
by smb＠research.att.com 17 Dec '03

17 Dec '03

`Hillary's Ominous Quotes of the Day': "AT A CERTAIN POINT, YOUR RIGHTS MUST BE ABRIDGED FOR THE PUBLIC GOOD." Sorry, that's a statement of fact. The interesting question is where one draws the line. Assume, for example, that you are a fervent believer in some religion that requires the sacrifice of unwilling outsiders. Should you be permitted to practice that religion? (Note: I said ``practice'', not ``believe in''.) Would the anarchist liberatarian next door to you be abridging your rights if he or she shoots back when you come to collect some victims? Even your own note acknowledged that rights aren't necessary absolute; you noted, in an exculpatory context, that The statement might simply be her response to a question about convicted rapists not having to submit to an AIDS test. As I said -- the interesting question is how and where one draws the line.

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T-Shirt stuff...
by Christian Void 17 Dec '03

17 Dec '03

Greetings. Could anyone who has order a t-shirt, but has not gotten a order confirmation PLEASE send me mail. I have a few orders sitting here that I have no size information or e-mail addresses for. Unless you want an XL, send me a note. Thanks. :) Christian Void /T71 | "I don't like it, and I'm sorry I | V/M/Research, Inc. cvoid(a)netcom.com | ever had anything to do with it." | P.O. Box 170213 Tel. 1+415-998-0774 | -Erwin Schrodinger (1887-1961) | SF, CA 94117-0213 * PGP v2.3a Public Key Available Via Finger *

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Freehdom Isn`t Freeh
by Duncan Frissell 17 Dec '03

17 Dec '03

New York Times, Monday, February 28, 1994 Business Day A PUSH FOR SURVEILLANCE SOFTWARE By John Markoff In the age of computer communications and digital telephone calls, the American people must be willing to give up a degree of personal privacy in exchange for safety and security, the head of the Federal Bureau of Investigation said. In an interview on Friday, Louis J. Freeh, the F.B.I. Director, defended proposed legislation that critics say would turn the nation's telephone network into a vast surveillance system. He said taxpayers would be asked to pay up to half a billion dollars to develop and deploy the necessary network software. The Administration wants to impose new technology that would enable law- enforcement agents to gather a wealth of personal information by monitoring citizens' calling patterns and credit card transactions over the telephone network --- and over the two-way cable television networks being planned by cable and phone companies. The system would go well beyond the current wiretapping technology, because much of the information could be gleaned without the police or F.B.I. actually having to eavesdrop on specific voice or electronic-mail conversations. "The costs are high, but you have to do a cost-benefit analysis," said Mr. Freeh, who insisted that fighting terrorists and criminals was the Government's intention --- not playing Big Brother to the citizenry. `A Credible Solution' "The damage to the World Trade tower and the economic interests of the country are conservatively estimated at $5 billion," he said, citing last year's bombing of the World Trade Center in Manhattan. "I think the American people will agree that this is a credible solution to the problem we face." The Administration is trying to line up Congressional support for the legislation, called the Digital Telephony and Communications Privacy Improvement Act of 1994, before having it formally introduced. Government officials say traditional wiretapping is becoming increasingly more difficult because more and more phone calls and data communications are transmitted as streams of digital information --- representing the ones and zeros understood by computers. Thousands of such calls may intermingle on a public-network circuit at any moment. Proponents of the legislation say new software placed on computerized network switching equipment is necessary to help law enforcement sort through this traffic. But executives of McCaw Cellular Communications, the nation's biggest cellular telephone company, told Mr. Freeh and White House officials at a meeting on Thursday that their newest telephone switches already provide the surveillance capabilities requested in the legislation. Moreover, privacy advocates say the Government can point to no case in which digital network technology alone has impeded an investigation. And they note that in the World Trade Center case, it was not electronic communications but mundane bungling of vehicle and warehouse rentals that led to arrests. An Electronic Portrait Such critics have long warned that in the information age, it is possible to build a detailed model of an individual's behavior, political and sexual preferences, social network and travel itineraries simply by examining telephone-calling patterns and credit card purchases. Some capabilities were demonstrated when law-enforcement agents pieced together a chronological list of phone calls made by the people accused of plotting and carrying out the attack in January on the figure skater Nancy Kerrigan. But the type of software the Clinton Administration wants to add to the public communications network would make possible much more detailed records of individuals' electronic activities. "It will be possible to develop a life-size portrait about you as a person," said Jerry Berman, executive director of the Electronic Frontier Foundation, a Washington privacy-rights lobbying group. "This is not just about a phone number." For the Administration, having taxpayers rather than communications companies pay for the system is meant to dilute industry criticism of the plan, which has met resistance since it was disclosed a few weeks ago. Congressional support is difficult to gauge. "The bill has some significant problems we need to resolve," said Representative Don Edwards, Democrat of California and chairman of the House Judiciary subcommittee on civil rights. "The profiling and the tracking aspect of the bill is something we are concerned abut." A version of the legislation was first proposed in 1991 by the Bush Administration at the urging of the Justice Department. But unlike that version, the new bill would limit the surveillance to public networks and not include company phone systems --- private branch exchanges, or PBXs --- or private corporate computer networks. Despite those changes, civil liberties groups and some industry executives say they are concerned that the scope of the new bill would give law- enforcement agencies new access to a vast amount of "transactional," or billing, information related to the setup of a telephone call. Under current law, obtaining a subpoena to obtain transaction data from the telephone company is easier than getting a wiretap warrant to eavesdrop on actual conversations, which requires a judge to find probable cause that a crime has taken place. Mr. Freeh met with telephone industry executives at the White House on Thursday and with Congressional leaders on Capitol Hill on Friday in an effort to attract support for the bill. He said in the interview that he was willing to compromise by adding safeguards for transactional information. "I understand the privacy concern," he said. "My real objective is to get access to the content of telephone calls. With respect to the extraordinary amount of personal information that is generated by this new technology, we would consider some way to block some of that information or raise the standard required to gain access. We're flexible on that." The F.B.I. Director said new digital communications technologies were making it more difficult for authorities to listen to conversations of suspected criminals who may be using cellular telephones or whose conversations may be carried as data streams in networks of fiber optic cables. Mr. Freeh said wiretapping had long been one of law enforcement's most effective tools. He cited examples in which it had been used effectively to prevent crimes, including a case in Chicago in which a terrorist was planning to shoot down an airliner with a Stinger missile. In that instance, Mr. Freeh said, The telephone networks involved were not advanced digital systems, but older analog networks that send voices as electronic patterns mimicking natural sound waves. But he said there had already been hundreds of cases in which attempted F.B.I. wiretaps had been thwarted by new digital communications technology --- not, he said, because the suspected criminals were necessarily trying to evade detection, but simply because the public-network technology made it difficult for agents to listen. Last year, a group called the Computer Professionals for Social Responsibility obtained Government documents through a Freedom of Information request indicating that an informal survey of F.B.I. offices in Newark, Philadelphia and Las Vegas, Nev., found no instances in recent years in which F.B.I. agents had encountered any technology- based problems in conducting wiretaps. Asked about those findings, Mr. Freeh said he was not aware of them. Several telephone industry executives who met with Mr. Freeh at the White House last week said that they were skeptical whether new legislation was needed and that they were concerned about provisions that would fine telephone companies up to $10,000 a day for failing to comply with the new law. "This is just new faces giving the same pitch," said one telephone industry vice president who attended the meeting and who had been opposed to the Bush Administration's version of the legislation. He spoke on condition of anonymity. Executives at the American Telephone and Telegraph Company said they did not believe there were significant technological problems that warranted new legislation. They also said they feared that the proposed legislation would undercut the privacy expected by customers. "Clearly the privacy concern is the biggest concern for A.T.&.T.," a spokesman for the company, Herb Linnen, said. He said the company would continue to meet with the White House and Justice Department in an effort to narrow the bill. Industry executives and privacy advocates have also warned about abuses of new surveillance technologies by telephone company insiders and computer vandals. But the F.B.I. Director said the protections in current analog telephone systems would be adequate to deter most break-ins. "This is always a threat," Mr. Freeh said. "But it's de minimus if you consider the alternative, which is not giving law-enforcement and intelligence agencies these capabilities." A White House official said that he believed opponents of the legislation were overreacting and that the law was a good compromise between privacy and law-enforcement needs. "The authority to gather transactional information already exists; I don't think this expands that authority," said John Podesta, the White House staff secretary. "We're open to talking through the issue with the privacy community." ----- Keyboarding by Lois Roth --- WinQwk 2.0b#1165

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Re: standard for stegonography?
by Jef Poskanzer 17 Dec '03

17 Dec '03

>Now that I think about it, one wouldn't have to sacrifice any bandwidth >whatsoever! As, the stego program could be made to do wrap-around >encoding. Indeed, that's what I implemented. The current man page is appended. --- Jef pnmstego(1) USER COMMANDS pnmstego(1) NAME pnmstego - insert a stegonographic message into a portable anymap SYNOPSIS pnmstego [-offset n] [-components rgb] [-bitsched 10010...] file [pnmfile] DESCRIPTION Reads a portable anymap as input. Hides another file within the anymap by changing the low-order bits of each pixel, and writes the modified anymap to standard output. Stegonography means "hidden writing" - it's for storing a message in such a way that an opponent won't even be sure that the message is there, let alone be able to extract, decrypt, and read it. Pnmstego lets you store a file in the low-order bits of a PPM or PGM image. For a typical maxval of 256, this means the pixel values will be changed by only 1/256, which should not be noticable to someone viewing the image. Only PGM and PPM images may be used - trying to hide a file in a PBM image would be easily visible, so it's not allowed. OPTIONS The program has a bunch of flags that let you specify varia- tions on exactly how the bits are hidden in the image. If you don't specify any flags, the default options give you a reasonable storage method, to wit: -offset 0 -components b -bitsched 1 Letting the options default like this has the advantage that you can send a stegoed file to someone without having to specify what flags you used. You can also put the file on a public FTP server for people to retrieve, without needing any other communication. However, there is a disadvantage: people who the file is not intended for will be able to extract it too. If the resulting file is recognizable in some way, for instance if it's encrypted by PGP, then some of the purpose of the stegonographic storage will have been compromised. (A PGP file has a standard header and stores, in cleartext, the keyid needed to decrypt a file.) So, if you want the file to be absolutely positively hidden, you can use non-default settings for the options. Just don't forget what settings you used, and remember that if you want to send the file to someone else you will have to communicate the necessary settings somehow. Now, as for what the options do: -offset Specifies how far into the image to start. If the file runs off the end of the image, it wraps around back to the beginning, so don't worry about specifying too large an offset. In fact, you can even specify an offset larger than the image size - the initial value gets wrapped around too (modulus). Basically, any 32-bit number can be used. -components This lets you specify which of the red, green, or blue color components is used for storing bits. You give it a string made up from one or more of the letters r, g, and b. The default is b, use only the blue component. See the section below on quantization for why the default isn't rgb. If the input image is a PGM file, instead of PPM, this option is silently ignored. -bitsched This lets you skip using some possible bit posi- tions in the image. If the file you're hiding is not so big that you need the whole image to store it, you can use this option to hide it better. The argument is just an arbitrary- length string of 1's and 0's - the 1's say which bit positions should be used, and the 0's which should be skipped. The default is to use all bit positions. QUANTIZATION Normally, to store an image in a colormapped file format such as GIF, you first run it through ppmquant. However, if you try to quantize, then stego, and then convert to GIF, you will find that the ppmquant step will fail with an error about too many colors. This is because the stego step increased the number of colors. You might think, ok, stego first, then quantize; nope, the quantization would destroy the stegonographic message. Here's what you do instead: quantize down to half the number of colors you want in the final file, and then use only one of the three color com- ponents to store the hidden file. Using only one bit per pixel, the number of colors can at most double. This is why the default for the -components flag is to use only blue. So, the pipeline to use is: ppmquant 128 image.ppm | pnmstego message.txt | ppmtogif > hidden.ppm SEE ALSO pnmdestego(1), pnm(5) AUTHOR Copyright (C) 1994 by Jef Poskanzer.

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Re: standard for stegonography?
by Jef Poskanzer 17 Dec '03

17 Dec '03

I wrote: >offset, wrap-around, bit schedules Actually, that interface is way too complicated and still not that secure. How about if the user just specifies a seed for a random number generator. Then that generator is used to make a *permutation* of the bit locations in the image, and the file's bits are stored in the permuted order. And look, this hides the file-length longword and any fixed file header real well, by spreading them through the image. Now I just have to find a simple but robust RNG that I can include in pbmplus, and some code to generate a permutation of a specified size. I'm not going to have ITAR problems with this, am I? RNGs are still legal to export? Oh, and to answer the original question: no standard. If this idea works, it's clearly better than existing stego systems at hiding the data; that's more important than interoperability. --- Jef

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Re: Dorothy Denning
by Black Unicorn 17 Dec '03

17 Dec '03

-> Also, I've gotten a message through to Ross Perot about our fight against Clipper, and how to reach me, so if I get a response, I'll let you guys know. Anthony <- Oh god, that is all the cause needs. I can see it now: "Transistor brain Ross Perot opposes it! It must be evil!"

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Re: standard for steganography?
by plaz＠netcom.com 17 Dec '03

17 Dec '03

Jim choate <ravage(a)wixer.bga.com> wrote: >I have played w/ stego some and w/ the present resolutions of images I dont >find the images have enough complexity to really hide a message of a useable >length, unless you break it up into several images. Present resolutions? What directions do you think it needs to go? Stego handles 24 bit TrueColor (actually 32 bit, but Romana wisely decided not to stuff data in the almost always blank alpha channel), and as many DPI as you have memory for. I don't think there is much call for deeper color resolution. It's true that GIF only accepts 8-bit color and the defacto standard internet transmision format for higher resolutions JPEG is a lossy compression that annhilates the message. Is this what you are refering to? >I use a function to measure the complexity of a image based on adjacent bit >changes. The more complex an image the more bit changes. I measure it thus: > ># of adjacent bit changes in image/ # of bits in image = complexity > >if the complexity is too low or too high (this is counter intuitive) then you >can't hide a message. Consider an image w/ only a few bit flippings, any >message that is inserted will cause the visual image to be distorted in a >noticable way (unless it is truely expressionistic). Now consider a image w/ >every other bit flipped (maximum complexity) which is in effect a >checkerboard. Any bits that get flipped change the pattern to a less complex >one (ie the checkerboard is broken up). Also you have to consider the effects >on edges and the standard deviation inherant in using anti-aliasing. This >will cause bits on the edge to be switched incorrectly for the algorith in >use. Since it is a trivial problem to measure the sd for various graphics >packages this makes a nifty test bed for finding imbedding images. Blank or >mono-chromatic areas also show the same type of errors. Yes, it is recommended that noisy images are used as the message envelope. Scanned or Frame-grabbed are good for this kind of thing. _______________________________________________________________________ Geoff Dale -- Cypherpunk/Extropian -- Plastic Beethoven AnarchyPPL - Anarch (Adjudicator) ExI-Freegate Virtual Branch Head plaz(a)netcom.com 66 Pyramid Plaza plaz(a)io.com Freegate, Metaverse(a)io.com 7777 "Subvert the domination paradigm!"

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Re: standard for stegonography?
by plaz＠netcom.com 17 Dec '03

17 Dec '03

Jef Poskanzer <jef(a)ee.lbl.gov> writes: >>Well, try using Stego on an 8 bit PICT, and see for yourself! >>It looks like a >slight< random noise filter was applied to >>the image - plausibly the sort of trouble one would have with >>a slightly imperfect scanner. > >Maybe colormaps on the Mac are always sorted? That would minimize >the visible effect of +-1 changes in index value. Colormaps on the Mac are not "always" anything, since creating custom pallettes is trivial, but yes, they usually are. For best stegonagraphy in 8-bit, I would recomend using the system greyscale pallette. (Greyscale images *almost always* sorted on the mac.) _______________________________________________________________________ Geoff Dale -- Cypherpunk/Extropian -- Plastic Beethoven AnarchyPPL - Anarch (Adjudicator) ExI-Freegate Virtual Branch Head plaz(a)netcom.com 66 Pyramid Plaza plaz(a)io.com Freegate, Metaverse(a)io.com 7777 "Subvert the domination paradigm!"

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It's the philosophy, stupid!
by frode＠toaster.SFSU.EDU 17 Dec '03

17 Dec '03

It's now quite a while since I promised to write something about how the U.S. is starting to look more and more like the Weimar Republic just before Hitler came to power. However, I am simply out of band- width, and will try to get away with recommending the book where I first picked up this idea: "Ominous Parallels" by L. Peikoff The book reveals the philosophical premises of today's Liberals *and* Conservatives and shows how they would fit right into Weimar. In the end, Hitler was the man who promised to implement the ideals of both the right (order, restraint of workers etc.) and the left (social programs, restraint of businessmen.) Both the Protestants and the Catholics praised Hitler, for "increasing the moral standard" of the country. Finally, Ayn Rand's "Atlas Shrugged" is a novel which offers a rather stunning commentary to the words of both Bush and Clinton. Indeed, it was "Atlas Shrugged" which finally prompted me to abandon the super-socialized Norway and move to the U.S.; and here I am watching it grow ever-more statist. :-) As for anyone already aware of / curious about Rand's philosophy, Objectivism, I'll be happy to (per email) answer questions, point them to discussion lists and so on. Frode Odegard

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No Subject
by nobody＠jarthur.claremont.edu 17 Dec '03

17 Dec '03

Hi All... No no answer to the swiss bank question... Duncan... if you KNOW positively then your answer is OK... otherwise if you are shooting from the HIP please refrain... A definitive answer to this question is needed... and currently its unknown... anon

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low-overhead encrypted telnet
by Jef Poskanzer 17 Dec '03

17 Dec '03

I've been talking about entrypted telnet with Craig Leres lately, and he came up with an interesting idea. The background is, sysadmins want encrypted telnet so that passwords don't fly around in the clear, but at the same time, they don't want to spend too many extra CPU cycles. I figured at least some sysadmins would resist installing an encryption-capable telnetd because of this concern about overhead. What you'd really like to do so satisfy these people is encrypt only when actually transmitting passwords. Problem is, that's hard to implement. Kerberos does it by supplying new versions of a dozen different programs, and it still only works within your organization, and even there it doesn't handle chained logins (telnet from host A to host B, then from host B to host C, etc.). It's hard because you have different levels of software trying to talk to each other. A solution that worked entirely within telnet would be a lot simpler. A compromise I thought of a while back is to encrypt the first few kilobytes and then switch to cleartext. This lets you log in securely, the average overhead for the session remains low, and there's no interaction between different software levels. But this also doesn't handle chained logins, if the second login comes later in your session. So here's Craig's idea: only encrypt the client-to-server direction. That's the only direction that passwords go, so it's secure; and it's low overhead because you generally type far fewer characters than you read. Just a tidbit for anyone working on encrypted logins. --- Jef

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clipper + enaction = illegal alternate encryption
by VACCINIA＠UNCVX1.OIT.UNC.EDU 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Jeremy(a)crl.com writes: >Now why bother going through all the trouble to take out the chip? Why >not just leave it in there and send RSA encrypted over your phone line? >Once they _DO_ decrypt your clipper, they will still have another barrier. >Leaving the chip in there does make it a little harder even for law >enforcement doesn't it? This is the reason all other forms of encryption will be outlawed if the clipper proposal goes through. I foresee at least two lines of enforcement. The first is that one is held in contempt of court (assuming they can find some charges to press) until you give them your key. How long can they keep you in the slammer on a contempt charge? This option is already available and seems to work, at least so far. The second is to make alternate encryption illegal and thus they will get you even if they have no evidence to charge you with. After all, if the police are monitering you AND you are encrypting information, you must be guilty, right? Encryption will be enough evidence to convict. This makes life easy for law enforcement and will surely be the next step after clipper. If they can't get you for the alleged crime you are committing then use of illegal encryption will provide a consolation prize. They really HAVE to make alternate forms of encryption illegal to make clipper of any value to them, despite the rhetoric we are now hearing (at least some people are hearing). Scott G. Morham !The First, VACCINIA(a)uncvx1.oit.unc.edu! Second PGP Public Keys by Request ! and Third Levels ! of Information Storage and Retrieval !DNA, ! Biological Neural Nets, ! Cyberspace -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLXModj2paOMjHHAhAQH4IgQAy+sqJeI1JqDgtR4kayOuo5ovzcVpxfVM JTi7ZgwLppw859cKhQgGzHfWezpDYQxrYGEfOH4JqFXWUlqEyVgrDhIw2PVMO95p IkGDrU90O/RkUFg9lrEuWvxSXJvKX52Cz6jN7tj7DxkdXYutpc2z80QiPY1mtXN7 wr7XySZ9dzI= =BVk0 -----END PGP SIGNATURE-----

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Insecurity of public key crypto #2 (reply to May)
by wet!naga 17 Dec '03

17 Dec '03

[The BBS I use seems to have brain damage. Apologies if this has already been posted.] >From: tcmay(a)netcom.netcom.com (Timothy C. May) >Subject: Re: Mac encryption >Date: Wed, 23 Feb 1994 09:56:40 -0800 (PST) > >Ron Davis writes: > >(quoting me [T.C.M.]) > >>>MacPGP, available by anonymous ftp from the soda.berkeley.edu site, is >>>the only one I know of using public key methods, and hence the only >>>one of real interest to Cypherpunks. > >The problem with symmetrical ciphers is one of *scaling*. > >Since a key must be exchanged with each other person, the total number >of keys growns rapidly as the community of participants increases. At >any stage, the key may be lost, stolen, observed, shared with the >Feds, etc. A community of 700 participants, as here on Cypherpunks, >would mean each person would have to generate, exchange (securely!), >and store 700 specific keys for use just with others. Anybody with 700 co-conspirators is asking for trouble, since at least one of them is sure to be a federal agent. Encryption is for concealing "sensitive" information. If it's not sensitive, why bother? If it is sensitive then you'd better be damn sure you can trust the person you're sending it to. >This is the famed "key distribution problem." > >With public key methods, this problem is largely solved. Each person >can generate his or her own key, publish the public key part of it, >and be done with it. It's not that simple. Terry Ritter has pointed out on sci.crypt that the problem with PGP is the validation of public keys used. In other words, the security hole in the use of PGP is not in the encryption methods used, or in the use of PGP itself, but in the possibility of being duped by someone (or some nefarious federal agency) spreading bogus public keys. It's not enough to have a public key which you believe is the public key of a person you wish to communicate securely with - you also have to be sure that the private key which corresponds to this public key is known only to that person, in other words, that the public key really did come from the person you believe it came from. If you get the (presumed) public key of some person X from some directory of public keys, or from some third party, how can you be sure it didn't originate with someone who wants to monitor all the encrypted messages being sent to X? Terry Ritter has explained how a third party can place themselves in the middle of encrypted communications between two people using PGP and monitor everything they say to each other - and this without having to crack RSA or IDEA. This method of eavesdropping applies only to public key encryption systems, not to secret key systems, so I suggest that the latter are still of interest (even to cypherpunks), not only for encrypting data that stays on your hard disk but also for encrypted communications. rom owner-cypherpunks Tue Mar 1 12:11:49 1994 Return-Path: <owner-cypherpunks> Received: by toad.com id AA28180; Tue, 1 Mar 94 12:11:49 PST Received: from wet.UUCP by toad.com id AA28156; Tue, 1 Mar 94 12:11:44 PST Received: by wet.uucp (/\=-/\ Smail3.1.18.1 #18.2) id <m0pbaUt-000CAaC(a)wet.uucp>; Tue, 1 Mar 94 11:52 PST Message-Id: <m0pbaUt-000CAaC(a)wet.uucp> Date: Tue, 1 Mar 94 11:52 PST From: wet!naga (Peter Davidson) To: cypherpunks(a)toad.com Subject: Insecurity of public key crypto #1 (reply to Mandl) Sender: owner-cypherpunks(a)toad.com Precedence: bulk [My BBS is having fits lately. Apologies if this has already been posted.] >Date: Wed, 23 Feb 94 12:13:57 EST >From: dmandl(a)lehman.com (David Mandl) >Subject: Re: Mac encryption > >The invention (discovery?) of public-key crypto changed the world, and >makes practical everyday use of crypto infinitely easier. Infinitely? You mean there is absolutely *no* difficulty involved in using PGP? I quit using it up quite a while back. Couldn't be bothered with the hassle. >It also makes >the kinds of specific things cypherpunks are interested in much more >practical (or POSSIBLE). Digital signatures, yes. I haven't had a need for 'em so far (I'm not setting up a digital bank). >If you correspond with hundreds of people on a >regular basis, including people you don't know and people you may send >something to once and never deal with again, it is impractical to say the >least to have to generate and exchange keys. Only "sensitive" information is worth encrypting and if you want to stay out of trouble you don't go giving sensitive information to someone you don't know. A certain mutual knowledge and trust between two people has to be establish before any exchange of sensitive information. >Why was public key crypto invented at all? Why are people interested in >using it? Practically, it's really fundamentally different from symmetric >crypto, which is of very limited use in the situation we're all in now >(anonymous communication, the net, quick hit-and-run dissemination of >information, digital signatures, etc., etc.). Crypto is for concealing information from those you don't want to see it. Public key crypto is thus not fundamentally different from symmetric key crypto. The difference is in communication of the encryption key, which is not a fundamental difference. Both kinds of crypto have problems when it comes to key distribution. In the case of secret key the problem is in keeping the key secret. In the case of public key the problem is in validating the public key. >PGP also has the "web of trust" structure built in. "Trust"? Sure. Just trust the person you got X's public key from (who got it from someone who got it from who knows?). So is X's public key really X's public key? Sure, just trust that it's so, then send X a message and trust that it won't be intercepted by whoever put out the bogus public key for X.

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