December 2003 - cypherpunks-legacy

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by Louis Cypher 17 Dec '03

17 Dec '03

Please unsubscribe me. It was ok when I owned my own system, but now that I sold it, I cannot keep up with all the traffic. It was fun.

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WiReD has a gopher (and its name was...)
by Anonymous 17 Dec '03

17 Dec '03

Newsgroups: comp.org.eff.talk,alt.wired From: kadie(a)cs.uiuc.edu (Carl M Kadie) Subject: Wired Magazine's gopher Message-ID: <CHBE7B.Jt(a)cs.uiuc.edu> Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL Date: Tue, 30 Nov 1993 17:06:46 GMT Wired Magazine has a gopher. It includes many articles. Try gopher gopher.wired.edu I've also added it to the CAF whatsnew server. Try gopher gopher.eff.org 5070 - Carl ANNOTATED REFERENCES (All these documents are available on-line. Access information follows.) ================= admin/access ================= Information on how to access one computer medium via another: access anonymous ftp via email, access gopher via email, access gopher via telnet, read netnews via gopher, read netnews via telnet, write netnews via email, ftp via gopher. ================= admin/whatsnewd ================= * Code for and description of "whatsnewd" (v. 0.42) (Connect your Gopher to "gopher.eff.org", port "5070" to play with it.) It is a gopher-protocol server. What it does: When a user gives a date (e.g. "1 day ago") or enters a dated bookmark (generated by a previous query), he or she gets a gopher menu of the gopher items that are new or changed since that date. ================= ================= If you have gopher, you can browse the CAF archive with the command gopher gopher.eff.org These document(s) are also available by anonymous ftp (the preferred method) and by email. To get the file(s) via ftp, do an anonymous ftp to ftp.eff.org (192.77.172.4), and get file(s): pub/academic/admin/access pub/academic/admin/whatsnewd To get the file(s) by email, send email to archive-server(a)eff.org. Include the line(s) (be sure to include the space before the file name): send acad-freedom/admin access send acad-freedom/admin whatsnewd -- Carl Kadie -- I do not represent any organization; this is just me. = kadie(a)cs.uiuc.edu =

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Statistics of Low-Order Bits in Images
by tcmay＠netcom.com 17 Dec '03

17 Dec '03

Several folks have recently mentioned the need to carefully look at the statistics/distributions of bit values in the low-order bits (least-significant bits, LSBs) of real-world images intended for steganographic use. I concur. This problem interests me. Material from Li and Vitanyi's "An Introduction to Kolmogorov Complexity and Its Applications," 1993, bears directly on the issues of "picture distance" and how much one can change an image before it's recognizably "different" or before filter programs can detect the presence (or absence) of characteristic structure in images. In this little article I'll be making some general points and reasoning informally about image statistics, picture distances, and the like. There's no doubt a more rigorous way to reason about these statistical properties, using sigmas and summations and Central Limit Theorems and the like, but I'm not that much of a real mathematician to be bothered with that. C'est la vie. Several points: 1. Probably not a pressing concern, yet. I expect few sites have LSB-analyzers, just as few folks are using LSB stegonagraphy. 2. Romana Machado's "Stego" program for the Mac is interesting, and may be useful, but it makes almost no effort to hide the _existence_ of the message bits, e.g., anyone with a copy of Stego can apply it to an image and recover the plaintext or ciphertext. (I mean in contrast to some of the schemes which require a copy of the original image, a kind of one-time pad approach, in which one XORs or subtracts the original image to see the "differences" in the LSBs--a cryptanalyst without the "reference" image is unable to extract any bits for further analysis.) (I suggest we keep these two models in mind. Proposal for jargon: "Type 1 Stego": No reference model needed: message bits are just the specified bits, e.g., LSB, or larger low-order bits. "Type 2 Stego": a reference model--an image or DAT or whatever--is needed to XOR with message to recover the plaintext or ciphertext (if more encryption was used originally).) 3. With fairly noisy 8-bit images, such as might be gotten by frame-grabbing a video image under poor lighting or focus conditions, my experiences at Intel (I ran an image processing lab, for electron microscope analyis of microprocessors) tells me that the lowest _several_ bits of each pixel are "noisy." Very noisy. The bottom bit is "almost purely noise" (also a dangerous term!). But I agree that more recent images need to be looked at and the statistics analyzed. Still, I suspect the bottom bit, the LSB, will be found to have Gaussian noise characteristics. Note also that images are often run through filters, as in PhotoShop, which can give Gaussian characteristics where before there were none. 4. Can "image analyzers" in the hands of border security/law enforcement be used to proseute holders of images that have such white noise characteristics in the LSBs? I doubt it. I interject this point here because an important long-term issue for stego is whether the "Crypto Authority" (resonance with Gibson's "Turing Authority") can make such images ipso facto illegal. I suspect this is hopeless, both because many images have these characteristics and because many people will massage their images to be this way, regardless of original camera-CCD characteristics. 5. All of these arguments apply to the LSBs in DATs. Ambient room noise, noise in microphones, thermal noise in the electronics, etc., all contributes to there being almost no "signal" in the LSB of a 16-bit CD or DAT sample of music. (There are anecdotal reports of people being able to hear effects here, and different noise-shaping filters may have audible effects at least some of the time. So, I do agree that these statistics ought to be looked at, eventually. Some of my audio magazines have articles on this, which I'll try to look at soon.) 6. Here's a strategy which may work OK even if the statistical patterns of the LSBs are not "completely random" (a dangerous term, of course). - take a plaintext or ciphertext and compress it with a good compressor (L-Z may not be enough to wring out all the structure and raise the entropy to the full 8 bits per character, for ASCII). A good encryption of the text should of course produce high entropy. - XOR the compressed (high entropy) text with the LSBs of the image. - the resulting LSBs should have _similar statistics_ as compared with the original image. "Noise" has been added, but no knew structure has been added. Consider a couple of examples to see this: Original image (in bits) : 1 0 1 0 1 1 0 1 1 0 1 0 1 0 1 1 1 1 0 1 Random 1s and Os: 1 1 0 0 1 0 1 0 1 0 0 0 1 1 1 0 1 0 1 0 Resultant Image (XOR): 0 1 1 0 0 1 1 1 0 0 1 0 0 1 0 1 0 1 1 1 (Another example: If one toggles all the bits in a binary image, the "Hamming distance" between the images is maximal, and yet the "picture distance" is very small, i.e., the images look nearly the same. The picture distance being small means the structure is the same, even though the Hamming distance is, by definition, the greatest it can be. This provides a powerful clue that there is a "lot of room" to manipulate images so as to pack bits into this "Hamming space" while still keeping the resulting pictures in a "tiny picture space volume.") Well, this is of coure not a proof, but gives a feel for why XORing with a high entropy image will not _add_ structure. However, it can certainly _remove_ structure! Which takes us back to the original issue of the statistics (structure) of the LSBs of images. If in fact there were "clumps" of 1s and 0s, "ridges" and "valleys" caused by camera/CCD characteristics, then XORing the LSB image with a "random" image will demolish this structure. This is nothing more than the role of the one-time pad....to remove structure but allow its immediate reconstruction on the other end. At least in this case one does not have to worry about the ciphertext _adding_ unwanted structure, only that it may _remove_ structure already present in the image (and perhaps "typical" of images not carrying stego bits). 7. A better approach may be to take two very similar images, perhaps successive frame grabs with the same camera/digitizer, and use the statistics of the LSBs directly as part of the "one-time pad" above (Type 2 Stego). This could be used to give the LSBs the same "structure" (ridges and valleys of pixel values, for example) as a "real image" but without leaking message bits. (More work needed here.) (I apologize for any vagueness here. Partly it is that I haven't worked this out completely. Partly it is the lack of a blackboard to draw pictures on--verbal descriptions get confusing after a while. And partly it is that this message is already too long and I want to wrap it up.) 8. None of this subtlety really matters too much, I suspect. An image or DAT contains _so much room_ for stego bits that the problem of finding a tiny fraction of message bits in megabytes or hundreds of megabytes (DATs) of noisy source material seems well beyond current crunch capabilties. Perhaps images being sent to some sensitive location could be given a quick analysis to see if the LSBs are "too regular," but even this I doubt. And at least the XOR method described above won't introduce new structure....at worst the images or DATs would appear to be "too random." Perhaps we need to paraphrase Eric's line: "Use a random image, go to jail." --Tim May -- .......................................................................... Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay(a)netcom.com | anonymous networks, digital pseudonyms, zero 408-688-5409 | knowledge, reputations, information markets, W.A.S.T.E.: Aptos, CA | black markets, collapse of governments. Higher Power: 2^756839 | Public Key: PGP and MailSafe available. Note: I put time and money into writing this posting. I hope you enjoy it.

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by Paul Gilberti 17 Dec '03

17 Dec '03

Please unsubscribe me. I really thought that this list was for serious discussion of crypto technology/news. Instead, I'm just tired of weeding through my mail of immature postings of posters who are afraid to post under their own names (DL), and all the traffic regarding the censorship of the same.

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democracy and L. Detweiler
by baumbach＠atmel.com 17 Dec '03

17 Dec '03

L. Detweiler is a champion of democracy. He has argued strongly for it here on this forum. I am not a supporter of democracy. A crowd of people has no greater rights than one person. L. Detweiler disagrees with this. I shall confront this disagreement with an example that strikes to its core. I propose a vote. This vote will have no time limit. If at any point you wish to change your vote you are free do so. This vote is non-binding on those who do not support democracy. This vote will be conducted publicly on this list. ======================================================================= VOTE: Proposition desist L. Detweiler will cease posting to the cypherpunks mailing list. He will no longer concern himself with the activities of those on the cypherpunks mailing list here or on any other forum. [I support]/[I Do not support] ======================================================================= L. Detweiler will be the only judge of the results of this vote. If he believes a majority of unique individuals carry this proposal one way or another, then by his honor and support for democracy he is bound by it. If he recants his support for democracy, then he is not bound by it. ------------------ I shall cast my vote here: I support Proposition desist. Peter Baumbach baumbach(a)atmel.com

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Re: The Cure
by hawkwind＠dink.foretune.co.jp 17 Dec '03

17 Dec '03

>It craves fame. It resents what it perceives to be the fame of the >better-known members of this list to be. It is jealous of that fame, >and wants some for itself. It is sick and ugly, small and unintelligent, >resentful of its underdeveloped brain and the fact that everyone he looks >up to instantly recognizes his stupidity. And now it has found a way to get >those very people to acknowledge it, discuss it, feel threatened by it. >It is used to rejection, so the endless repeats of it mean nothing. And >then even less in the face of the warm glow at the center of the >Cypherpunks collective attention. > >This is the first and the last word I'll ever write about about it. >If we all did that, it would go away. > >Coerr > REALLY excellently stated! Great analysis of the nature of the problem. Thank you, do you mind if I quote this to others? Alas, though, I can not from long and bitter experience agree with you about the solution. In the real world physical verbal/facial expressions of disapproval and disdain might rapidly rid the group of the problem person, but in cyberspace, such traditional cultural prods are non-existent. The aberrant user KNOWS he faces no meaningful penalties or censure and thus has no inducement not to continue his chaotic ways. I do feel that in addition to the observations you made above, that such people often take sheer perverse delight in the mere poisoning of the creativity of the group being creatively atrophic themselves.

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Who is this Detweiler guy anyway?
by an48848＠anon.penet.fi 17 Dec '03

17 Dec '03

As a fairly recent addition to this list, I'm unfamilliar with the history of cypherpunks. Can anyone enlighten me? Thanks. ------------------------------------------------------------------------- To find out more about the anon service, send mail to help(a)anon.penet.fi. Due to the double-blind, any mail replies to this message will be anonymized, and an anonymous id will be allocated automatically. You have been warned. Please report any problems, inappropriate use etc. to admin(a)anon.penet.fi.

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Re: Knights who say NII (was Crypto(A), govt & NII)
by fnerd＠smds.com 17 Dec '03

17 Dec '03

> Steve Witham writes: > > > Giving the government savvy advice, telling them they should do whatever > > will promote, say, competition or open forums...what effects will these > > have? They may provide justifications, expertise and targeting info > > for interventions, for instance. New ways to get involved... Mike Godwin replies: > The government is already tempted to get involved, all the time. We can't > make the government go away by resolving that it would be nice if they > weren't around. Best to work from where we are, not where we'd like to be. Sure, I agree. It's just, will the process-that-be have a tendency to be encouraged to intervention in general, by positive-sounding things in what you say. > > I can't think of one positive thing (as opposed to the negative thing, > > disengagement) government can contribute to the goals of EFF. On being true police, see below. > Government is not the only potential source of harm--private industry can > be plenty harmful. Private business can be nasty, slow and unhelpful, but short of physical sabotage and threats, they can't do nearly the kind of harm and prevention of alternatives that government does. > > ...the most centralized organization in the world as the > > decentralist's tool or ally doesn't seem workable to me. The > > means clashes against the ends. > > I don't see how. One actually can use a weapon to keep the peace, for > example. Yes, you're right. I wasn't thinking about that because I assumed there's a minimum of physical crime in the communications industry. But now that I think about it, there's one thing State governments could limit: local governments' interference (franchises) in communications. But other than real basic policing like that, the means clash with the ends. Government is okay at nabbing true bad guys, not at trying to steer people in good directions. > > Telling a bull that he should make whatever > > positive contributions he can to the china shop...is worse than just > > not mentioning that there are none. > > I think you're reasoning from your conclusions here, not toward them. Well, sure, I'm talking from my view of how things are. Mostly I'm just saying that the *need* for positive government involvement is dubious while the *danger* is obvious in the current state of things, and if you aren't always saying that, then your well-informed comments and laudible goal statements can be misconstrued more easily, because in certain circles, radical deregulation is not assumed. That's my not-so-humble-but-trying (IMNSHBTO?) point in a nutshell. Your participation without this particular sternness, may, as one side-effect, encourage and assist where we all won't be happy it did--and maybe it'll fail to push through the single most helpful idea. I know, it's not your particular hobbyhorse. It's just what I'm afraid will happen. > What's more, government ain't the only bull in this shop. Although the FCC is smaller than AT&T, there's nothing in private industry with the momentum, power and difficulty of correcting that our layers of government have. Business without the power of government behind it (which status-quo businesses do have right now) faces much more immediate corrective pressure than government. Even combinations of big nasty companies are less of a problem. Throw me in that briar patch, puh-*leeze*, it's better than this one. -fnerd(a)smds.com quote me -----BEGIN PGP SIGNATURE----- Version: 2.3a aKxB8nktcBAeQHabQP/d7yhWgpGZBIoIqII8cY9nG55HYHgvtoxiQCVAgUBLMs3K ui6XaCZmKH68fOWYYySKAzPkXyfYKnOlzsIjp2toust1Q5A3/n54PBKrUDN9tHVz 3Ch466q9EKUuDulTU6OLsilzmRvQJn0EJhzd4pht6hanC0R3seYNhUYhoJViCcCG sRjLQs4iVVM= =9wqs -----END PGP SIGNATURE-----

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What recipient-end mail filters are available?
by Anthony Garcia 17 Dec '03

17 Dec '03

I'm aware of two mail-filtering systems that operate at the recipient's end, procmail and Elm filter. Are there others? -Anthony Garcia agarcia(a)neosoft.com

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Entropy, Randomness, etc.
by jerry＠terminus.dell.com 17 Dec '03

17 Dec '03

With all this talk about entropy, randomness, and gaussian distributions, I'm hoping we can clear up some of the confusion that I am having. My understanding of a random number is a number is generated from two or more unrelated events. In order for this number to be most useful cryptographically, it needs a even distribution. This distribution is such that any one number in the range of possible values is equally probable as any other number. Does this make this distribution a gaussian distribution? Maybe I just don't understand the theory behind the random numbers well enough, but with all of these terms floating around it is hard to keep track. The reason I want to get some of these things clarified, is because I am becoming more interested in some of the analysis people have been talking about being possible. Also how are these statistical measurements done? Is it as simple as a histogram? (useful for simple alphabet transliterations). Are we talking frequency analysis with FFTs and more advanced things? How do we measure the entropy of a random number, or a series of random numbers? Have people on the list done this, or is this still in the range of people that do math and number theory for a living? Give a particular set of data used to generate a random key, such as, a unix box's /dev/mem, how can one measure the number of bits of entropy? These topics are probably covered in some of the basic books in the field, but all of the reference's I've been able to locate don't go into specifics of how to measure the quality of random numbers. Unless some measurements are made, you can't really be sure that those /dev/mem MD5 hashes don't come up the same 10%, 30%, or more of the time. It seems that a lot of assumptions are being made about what is good and what isn't. I plan to build a hardware random number generator and I have a couple of different circuits to do it, but I've heard some comments about some types of noise not being "good" cryptographically. -- Jeremy Porter ------------- Systems Engineering -------- Dell Computer Corp. ------ jerry(a)terminus.us.dell.com ---- --- 70 4F BD AE 6D E9 D2 66 48 18 8B E7 64 7F 59 8F --- Support your Second Amendment rights to encryption technology.

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