December 2003 - cypherpunks-legacy

CELP C Code - where?
by charliemerritt＠BIX.com 17 Dec '03

17 Dec '03

While skimming over cypherpunk mail a couple of days ago I saw a reference to some C code for CELP de/encoding voice. Where can I get a look? Email charliemerritt(a)bix.com

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*2* remailers have been attacked
by Sameer 17 Dec '03

17 Dec '03

I'm wondering if any people here running remailers have been having trouble lately. I'll explain. (And try not to act paranoid.) I ve been running a remailer on cs60a-qu(a)cory.eecs.berkeley,edu, and one day the account was disabled. I mailed the responsible administrator, and he said that it was because I didn't reply to his mail (I never check that account's mailbox, 'cause I hardly use it.) telling me that I should see him in person about possible email abuse. My account was going to be disabled on the 20th anyway, so I really didn't worry about it-- I had finals to worry about. So now I'm in Boston, and I call netcom, (where I run another remailer) and they tell me the account is being investigated because the account was used to break in somewhere. I know *I* did no such thing. I finger the account (by calling all the way across the damn country to my berkeley account) and it says that my las login was from soda.berkeley.edu, even though my las login was from the Berkeley dialup, not soda. I was told to call the netcom office tomorrow morning about the issue. My question is whether anyone else running a remailer has been attacked lately. In paranoia, Sameer (Please pardon any irrationallity.. phone calls from Boston->Berkeley are *not* cheap, and it's pissing me off.)

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Signing Images Not So Useful Now
by tcmay＠netcom.com 17 Dec '03

17 Dec '03

I don't think signing digital images is especially useful right not. This is not to say we shouldn't discuss it, or that someone out there won't make some bucks on such a product. Some points: * signing at the digital camera level is the most unlikely, currently, as most digital images are currently made by _scanning_ conventional slides or prints. (Slide scanners are readily available, with >1200 dpi, and even higher, resolution.) * as others have noted, almost all digital images are further massaged in PhotoShop or the like. Even Nick Szabo's "picture distance" idea is of marginal use, as many common filter operations introduce very large picture distances and/or Hamming distance. Determining "alikeness" metrics of an image and a suspected forgery or copyright violation will be a challenge. (Could be a nice little niche business for a "expert witness" on such things, though.) * most ripped-off images are of course done by using scanners. All those "Playboy" and "Penthouse" images you see on the Net are done with scanners. (Both Playboy and Penthouse offer on-line services, so I suppose it's possible some of the bootleg images are in fact digital copies. In these cases, a signature might reveal the copyright violation. A simple Gaussian blur in PhotoShop would of course erase most conceivable signatures. There may be some way to introduce something that can't be easily blurred away, though...) * the most common means of detecting forgeries and copyright violations is of course the human recognition of such images, the recognition that an image came from a well-known source. --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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Re: Error-Qualifying Signatures
by collins＠newton.apple.com 17 Dec '03

17 Dec '03

(Oops, forgot to include 'punks, sorry Nick) Nick Szabo asks: >Is a one-way hash function or digital signature possible with the >following property: signature verification doesn't just determine >the boolean altered vs. pristine, but also shows the picture >distance between the altered and original? This is possible. It is not a desirable quality for secure-hashes in most other situations because it compromises the privacy of the original message. Hash functions are usually designed specifically to avoid this. Scott Collins | "Few people realize what tremendous power there | is in one of these things." -- Willy Wonka ......................|................................................ BUSINESS. voice:408.862.0540 fax:974.6094 collins(a)newton.apple.com Apple Computer, Inc. 5 Infinite Loop, MS 305-2B Cupertino, CA 95014 ....................................................................... PERSONAL. voice/fax:408.257.1746 1024:669687 catalyst(a)netcom.com

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Re: Signing pictures -- how hard, how long?
by Peter Wayner 17 Dec '03

17 Dec '03

I think signing photographs and movie images is a difficult problem. Why? Because one flipped bit will completely screw up the hash function. Errors on these tapes happen rarely, but most video manufacturers aren't really going to bother worrying about occasional bit errors because they're usually invisible to the eye. Why waste all that extra effort on error correction if it's not worth the trouble. So signed photographs will also need to contain all of the error correction necessary and that will make them more expensive. This isn't any real cost on a general purpose machine, but it matters in some places.

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Re: Signing pictures -- how hard, how long?
by kqb＠whscad1.att.com 17 Dec '03

17 Dec '03

Alan (Miburi-san) Wexelblat <wex(a)media.mit.edu> said: > The problem with bit-rot is a more significant one. In this case you might > want to compute your hash not over every bit of the image, but over the > "significant" ones. That way if you lose low-order bits that no one cares > about your signature is still valid. If your signature does not include the low order bits of your image, then someone could embed a secret message in those low order bits (via Romana Machado's "Stego," for example) and your signature still would be valid. I wouldn't want my signature over someone else's steganized message. I'm sure there's a simple fix for that, such as ensuring enough bit rot to blow away any but the most error-tolerant steganography or including a disclaimer of responsibility for the low-order bits, but I couldn't resist pointing it out. Kevin Q. Brown INTERNET kqb(a)whscad1.att.com or kevin_q_brown(a)att.com

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MTGS: Conflict Alert
by edgar＠spectrx.saigon.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- If the Cypherpunks schedule their January '94 meeting on the 2nd Saturday, Jan 8, that will conflict with a party announced by visiting Exi fireman Harry (Hawk) Shapiro. Harry said: As I announced a month or so ago, I am holding a party on Jan 8, at the Shearaton Palace Hotel in San Fran. Jan 8th is the last day of MacWorld. Hopefully a group of us will meet for dinner arround 6pm. The party will start about 8 or 8:30. As I doubt either Harry or MacWorld will change their schedules for our benefit, I suggest the Cypherpunks consider (and announce with plenty of lead time) changing theirs to the Saturday after (Jan 15) (The Saturday before is New Year's day). -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLQ3ZId4nNf3ah8DHAQEJ6gP9GnsdIuxnTK2fYDuVKEULDOCnLzBcYJKZ omv6A42BhRjBxDh5qnKbJXjjN7P4rIzsI+0F2GMO/LPyx9IQnTZ9iGJ2Q4hteL97 ueL/BirVX//39mNwmf9DsWej59GEzKUgBbsjv3E14aHsOJhO6wWh9Swg3qZeJJuR fVSWJP3ynCY= =0bKX -----END PGP SIGNATURE----- -- edgar(a)spectrx.saigon.com (Edgar W. Swank) SPECTROX SYSTEMS +1.408.252.1005 Cupertino, Ca

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Re: MTGS: Conflict Alert
by plaz＠netcom.com 17 Dec '03

17 Dec '03

>If the Cypherpunks schedule their January '94 meeting on the 2nd >Saturday, Jan 8, that will conflict with a party announced >by visiting Exi fireman Harry (Hawk) Shapiro. Harry said: > > As I announced a month or so ago, I am holding a party on Jan 8, > at the Shearaton Palace Hotel in San Fran. > > Jan 8th is the last day of MacWorld. Hopefully a group of us will > meet for dinner arround 6pm. The party will start about 8 or > 8:30. > >As I doubt either Harry or MacWorld will change their schedules for >our benefit, I suggest the Cypherpunks consider (and announce with >plenty of lead time) changing theirs to the Saturday after (Jan 15) >(The Saturday before is New Year's day). Actually, there were plans to move the CyPunks meeting to Sat, Jan 15 anyway, since Jan 8th already conflicts with something else (Usenix? something Unix-y). Of course, the 15th is when the ExI-BATF (Extropy Institute - Bay Area Transhumanist/Task Force, for the extropianly-impaired) meeting would normally be held. I think we can ask Dave Krieger to put this off one week to the 22nd. If so, then I'll be happy. What d'ya say Dave? _______________________________________________________________________ Geoff Dale -- insert standard disclaimers here -- Plastic Beethoven plaz(a)netcom.com ExI-Freegate Virtual Branch Head plaz(a)io.com 66 Pyramid Plaza Cypherpunk/Extropian Freegate, Metaverse(a)io.com 7777 "Once you've gone plastic, you can never go back."

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Re: anonymous video rental store
by pierre＠shell.portal.com 17 Dec '03

17 Dec '03

> (A less obvious problem with the scheme is that the store could use > surveillance cameras to identify which tapes the customer selected, but I > chose to ignore that problem.) An other way to cheat would be also to process the returns faster... In the US (California?), since a well known case, (sorry, no bibliographically correct reference is at hand here) it is illegal for video stores to disclose rental records anyway. [Knowledgeable videomaniacs are welcome to fill in detailed references and whether it is illegal to collect such records, or just to misuse them. I seem to remember also that video stores cannot market their customer lists (as mailing lists). Before I spread anymore rumors, anybody knows the details? (It's probably no use asking somebody in a video store, they would be the last ones to know :-) a problem of our current legal system...] In any event, the case of concern when trying to build protocols and hardware for anonymous video rental is when the store personel is dishonnest. There is little point in trying to postpone this consideration. Pierre Uszynski pierre(a)shell.portal.com

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Re: signing pictures
by wcs＠anchor.ho.att.com 17 Dec '03

17 Dec '03

One reason that signing pictures could be useful is so that you could tell that a given picture came from, say, FoobarFoto Mark IV Camera Serial #32767, which lets you know that the photo was digitally retouched after it was taken. Yes, it's easy for someone to transform that into an unsigned picture, simply by twiddling a few bits (doing so at the end of the bitstream lets you minimize any corruption, btw), but you can at least be sure that a signed video or still picture was faked in real-space before digitizing it... and it's easier to detect those fakes, though reputable publications like the National Enquirer and the TV news programs showing exploding cars still have trouble on occasion :-) Bill # Bill Stewart NCR Corp, 6870 Koll Center Parkway, Pleasanton CA, 94566 # Voice/Beeper 510-224-7043, Phone 510-484-6204 # email bill.stewart(a)pleasantonca.ncr.com billstewart(a)attmail.com

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