December 2003 - cypherpunks-legacy

harris.statement (fwd)
by Mike Godwin 17 Dec '03

17 Dec '03

Forwarded message:

1 0

clipper_q-and-a.txt (fwd)
by Mike Godwin 17 Dec '03

17 Dec '03

Forwarded message:

1 0

wh_press_secy.statement (fwd)
by Mike Godwin 17 Dec '03

17 Dec '03

Forwarded message:

1 0

Re: STEG: a real-life use for steganography
by fnerd＠smds.com 17 Dec '03

17 Dec '03

Eric talks about a hypothetical system S which he discussed with real acquaintance X of country C (with repressive government G), for stegging information I in through exogenously-produced CDs of indigenous music M. One problem is that S is proposed for use by lots of people in C. That means the whole system won't be a secret for long. Soon G will know not only which records and which equipment to ban, but also the passphrases for the records--so why encrypt or even camoflage it? Maybe making copies of existing popular records would help. Classics that lots of people already have. Are there already records produced for C but manufactured outside of C? Do they import music popular outside C? > -- A facility to gather the data being put on the disks. This by > itself is no trivial task, since it involves the collection of many > disparate sources. Maybe the newsgroup you mention is just the thing for the second-to- last step in the chain. It can combine efforts of people who don't have to know each other. > -- An encryption system for the arranged data. Such a system can't > treat the data as one long stream, because of the segmented nature of > the data. There's also the problem of recovering from errors on the CD. > The ability to mount the CD as a file system would be good > leverage for other programmers. > -- A decryption system to get the data off the CD. Can most CR ROM drives read the raw music format? Many? If not, can the bit stream to the ADC in a CD player be intercepted? Maybe the best hardware from a physical camoflage standpoint would be those little CDROM drives that double as "walkmen". > A system to make rememberable sentences out of an > arbitrary 128 bits (and the inverse) would be useful to facilitate > word of mouth. Isn't it good enough to always start with sentences invented by people and encode into bits? > encoding and error correction systems used in CD's. I do know that > they are not simple, being much more than bit-correcting linear codes. I think when they're not giving you exactly what you put in, they're doing desparate things like repeating the last few milliseconds. So about all you can do is put CRCs and IDs on blocks (maybe small blocks?) and be able to deal with lost and misplaced blocks. It might be useful to have signatures on block boundaries so you could recognize them out of continuous streams. Maybe you would just take two blocks worth of data and slide your buffer along one byte at a time till you got a good CRC...but by then you would have received a lot more data. Better have a long buffer. > -- A standard for the encoding of file system data onto these low > bits. This should be a separate document, even though the design of > this will be influenced by the bit encoding standard. Some adaptation > of existing file system standards may be appropriate. Here, too, you need to deal with lost blocks. Having one copy of the root of the index might not be great. Also, assuming you're using modified CD players instead of CDROM drives, you might want to take advantage of the music track structure. -fnerd quote me - - skip sweet sweetbacks badass skipjack song, jack. 3x, fast. -----BEGIN PGP SIGNATURE----- Version: 2.3a aKxB8nktcBAeQHabQP/d7yhWgpGZBIoIqII8cY9nG55HYHgvt3niQCVAgUBLMs3K ui6XaCZmKH68fOWYYySKAzPkXyfYKnOlzsIjp2tPEot1Q5A3/n54PBKrUDN9tHVz 3Ch466q9EKUuDulTU6OLsilzmRvQJn0EJhzd4pht6hSnC1R3seYNhUYhoJViCcCG sRjLQs4iVVM= =9wqs -----END PGP SIGNATURE-----

1 0

For Pr0duct Cypher: faster mp_inv
by nobody＠shell.portal.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- Pr0duct Cypher wrote: > How big should the blinding factor be? I am not sure. Right now, it is set > to the modulus minus one byte. This is certainly secure, but it takes a > long time to unblind because mp_inv is a slow operation. If you know how > long it needs to be, feel free to change it. PGP's mp_inv is needlessly slow. It works OK for the little numbers they normally use ("e" exponents) but bogs down for big numbers. Fortunately I wrote a fast version of mp_inv some time ago just for this application (blinding). You might say it is "blindingly" fast! Here it is, from my private copy of pgp source. With this you can choose anything for your blinding. You will probably want to change it to use your safemalloc. #ifdef OLD_MPINV /* Replaced by a faster routine, below */ void mp_inv(unitptr x,unitptr a,unitptr n) /* Euclid's algorithm extended to compute multiplicative inverse. Computes x such that a*x mod n = 1, where 0<a<n */ { /* The variable u is unnecessary for the algorithm, but is included in comments for mathematical clarity. */ short i; unit y[MAX_UNIT_PRECISION], temp[MAX_UNIT_PRECISION]; unit gcopies[3][MAX_UNIT_PRECISION], vcopies[3][MAX_UNIT_PRECISION]; #define g(i) ( &(gcopies[i][0]) ) #define v(i) ( &(vcopies[i][0]) ) /* unit ucopies[3][MAX_UNIT_PRECISION]; */ /* #define u(i) ( &(ucopies[i][0]) ) */ mp_move(g(0),n); mp_move(g(1),a); /* mp_init(u(0),1); mp_init(u(1),0); */ mp_init(v(0),0); mp_init(v(1),1); i=1; while (testne(g(i),0)) { /* we know that at this point, g(i) = u(i)*n + v(i)*a */ mp_udiv( g(iplus1), y, g(iminus1), g(i) ); mp_mult(temp,y,v(i)); mp_move(v(iplus1),v(iminus1)); mp_sub(v(iplus1),temp); /* mp_mult(temp,y,u(i)); mp_move(u(iplus1),u(iminus1)); mp_sub(u(iplus1),temp); */ i = iplus1; } mp_move(x,v(iminus1)); if (mp_tstminus(x)) mp_add(x,n); mp_burn(g(iminus1)); /* burn the evidence on the stack...*/ mp_burn(g(iplus1)); mp_burn(v(0)); mp_burn(v(1)); mp_burn(v(2)); mp_burn(y); mp_burn(temp); #undef g #undef v } /* mp_inv */ #else /* OLD_MPINV */ /* Faster mp_inv, based on "Fast Multiplicative Inverse in Modular * Arithmetic", J. Gordon, in Cryptography and Coding, edited by * Henry J. Beker and F.C. Piper, 1989. * The mapping from the variables in that paper to our variables is, * roughly, M->n, X->a, HCF->u(iminus1), U->u(i), temp->u(iplus1), * INV->v(iminus1), V->v(i), temp->v(iplus1). We rotate the assignment to temp * and INV in their 2nd block of code. */ void mp_inv(unitptr x,unitptr a,unitptr n) /* Euclid's algorithm extended to compute multiplicative inverse. Computes x such that a*x mod n = 1, where 0<a<n */ { /* The variable u is unnecessary for the algorithm, but is included in comments for mathematical clarity. */ int shifts; int i = 1; int enterloop; unit vcopies[3][MAX_UNIT_PRECISION], ucopies[3][MAX_UNIT_PRECISION]; #define u(i) ( &(ucopies[i][0]) ) #define v(i) ( &(vcopies[i][0]) ) /* Modify this to do one division at the beginning. That makes it faster. mp_move(u(0),n); mp_move(u(1),a); mp_init(v(0),0); mp_init(v(1),1); mp_init(v(2),1); */ mp_move(u(0),a); mp_init(v(0),1); /* Init U to n%a, V to -n/a. */ mp_udiv(u(1), v(1), n, a); mp_neg(v(1)); mp_move(v(2),v(1)); do { enterloop = 0; shifts = -1; if (mp_compare(u(i),u(iminus1)) > 0) /* if U > HCF then */ mp_init(u(iplus1),0); else { enterloop = 1; mp_move(u(iplus1),u(i)); /* temp := U */ while (mp_compare(u(iplus1),u(iminus1)) <= 0) { /* temp<=HCF */ ++shifts; mp_shift_left(u(iplus1)); /* leftshift(temp,1) */ } mp_shift_right_bits(u(iplus1),1); /* rightshift(temp,1) */ } mp_sub(u(iminus1),u(iplus1)); /* temp := HCF - temp */ mp_move(u(iplus1),u(iminus1)); i = iplus1; /* V := tempV, tempV := INV, INV := V, */ /* U := tempU, tempU := HCF, HCF := U; */ /* (All simultaneous) */ if (enterloop) { while (shifts--) mp_shift_left(v(i)); /* leftshift(V,shifts) */ mp_sub(v(iplus1),v(i)); /* temp = temp - V */ } mp_move(v(i),v(iplus1)); /* V := temp */ } while (testne(u(i),0) && mp_compare(u(i),u(iminus1))!=0); mp_move(x,v(iminus1)); if (mp_tstminus(x)) mp_add(x,n); mp_burn(u(0)); /* burn the evidence on the stack...*/ mp_burn(u(1)); mp_burn(u(2)); mp_burn(v(0)); mp_burn(v(1)); mp_burn(v(2)); #undef u #undef v } /* mp_inv */ #endif /* OLD_MPINV */ -----BEGIN PGP SIGNATURE----- Version: 2.1e iQCVAgUBLVLeoArkCJ6S8691AQH9/QP+LRZ4oXiwNTUkpK7/4uJWhvJCLHPsCNsR YXruZCgY1448DRpbNV4PCtFg/GhDqvJpsWtWOy3lFZIO9zxrDb/tsIfruIJJZr0w lpWhhY+xUJNQYuqgu69EOY2IhJPiyZ+AyMuE4uYscuxEKmAEdLm/BAypX1zNplue NdURpM+pPw4= =f7BH -----END PGP SIGNATURE-----

1 0

UNSUB
by MCALVINK＠ccmail.sunysb.edu 17 Dec '03

17 Dec '03

UNSUBSCRIBE m calvinkoons

2 1

clipper_q-and-a.txt
by nobody＠soda.berkeley.edu 17 Dec '03

17 Dec '03

Q. Who will hold the escrowed keys? A. The government.

1 0

wh_press_secy.statement
by nobody＠shell.portal.com 17 Dec '03

17 Dec '03

The following is a self contradictory statement, if considered to apply for the time period of the next 20 years as the govenment's policy, and it down right PISSES ME OFF. Fuck you, government. >The Administration believes that the steps being announced today >will help provide Americans with the telecommunications security >they need without compromising the capability of law enforcement >agencies and national intelligence agencies. Today, any American can >purchase and use any type of encryption product. The >Administration does not intend to change that policy. Nor do we have >any intention of restrictiog domestic encryption or mandating the use >of a particular technology.

1 0

Food for thought
by Perry E. Metzger 17 Dec '03

17 Dec '03

In conjunction with the latest Big Brother Chip announcements, I've dug up an article I wrote for the net a while back. Some of it seems a bit weak now, but so much of it still feels current that I decided to repost it here. ---------------------------------------------------------------------- Newsgroups: sci.crypt Subject: The Escrow Database. Summary: Expires: References: <1993Apr18.034352.19470(a)news.clarkson.edu> <strnlghtC5puor.704(a)netcom.com> <bontchev.735230663@fbihh> Sender: Followup-To: Distribution: Organization: Partnership for an America Free Drug Keywords: Here is a disturbing thought. Now, we no longer live in the days of big filing cabinets. We live in the electronic age. I asked myself, how big could the escrow database get? How hard might it be to steal the whole thing, particularly were I an NSA official operating with the tacit permission of the escrow houses? (We can pretend that such will not happen, but thats naive.) Well, lets see. Ten bytes of each escrow half. Lets asume ten bytes of serial number -- in fact, I believe the serial number is smaller, but this is an order of magnitude calculation. We assume 250*10^6 as the population, and that each person has a key. I get five gigabytes for each of the two escrow databases. Fits conveniently on a single very valuable Exabyte tape. This can only get easier with time, but who cares -- I can already hold all the clipper keys in the country in my pocket on two 8mm tapes. Admittely, they will think of safeguards. They won't put the whole database on one disk, prehaps. Maybe they will throw stumbling blocks in the way. This changes nothing -- they keys will be needed every day by hundreds if not thousands of law enforcement types, so convenience will dictate that the system permit quick electronic retrieval. At some point, with or without collusion by the agencies, those exabyte tapes are going to get cut. Dorothy Denning and David Sternlight will doubtless claim this can't happen -- but we know that "can't" is a prayer, not a word that in this instance connotes realism. With two exabyte tapes in your pocket, you would hold the keys for every person's conversations in the country in your hands. Yeah, you need the "master key" two -- but thats just ten bytes of information that have to be stored an awful lot of places. Come to think of it, even if the NSA getting a copy of the database isn't a threat to you because unlike me you have no contraversial political views, consider foreign intelligence services. You know, the ones that David Sternlight wants to protect us from because of the evil industrial espionage that they do. The French apparently do have a big spying operation in friendly countries to get industrial secrets, so he isn't being completely irrational here (although why our companies couldn't use cryptosystems without back doors is left unexplained by those that point out this threat.) Presumably, foreign intelligence services can get moles into the NSA and other agencies. We have proof by example of this: its happened many times. Presumably, someday they will get their hands on some fraction of the keys. You can't avoid that sort of thing. Don't pretend that no one unauthorized will ever get their hands on the escrow databases. We crypto types are all taught something very important at the beginning of intro to cryptography -- security must depend on the easily changed key that you pick to run your system, and not on a secret. The escrow databases aren't the sorts of secrets that our teachers told us about, but they are the sort of big secrets they would lump into this category. Imagine trying to replace 100 million Clipper chips. I cannot believe that the NSA or whomever it is thats doing this doesn't realize all this already. They are too smart. There are too many of them who have made their bones in the real world. I suspect that they know precisely what they are doing -- and that what they are doing is giving us the appearance of safety so that they can continue to surveil in spite of the growth of strong cryptography. I suspect that they realize that they can't put things off forever, but they can try to delay things as long as possible. Who knows. Maybe even some of the higher ups, the inevitable bureaucratic types that rise in any organization, really do believe that this scheme might give people some security, even as their subordinates in Fort Meade wring their hands over the foolishness of it all.

1 0

Re: Running regularly
by Matthew Bernardini 17 Dec '03

17 Dec '03

> Matthew Bernardini <matthew(a)gandalf.rutgers.edu> wrote: > > > Why not make two shell scripts, one that sleeps for so long (say 20 minutes) > > using the unix sleep command, and then calls the remailer scripts in an > > infinite while loop. This would work if you set it up as a background > > process,and you don't need to be root for it to work. Only downsides are > > that when the machine crashes you have to log back in and restart script, > > your sleep command will always be in the top window if your sys-admin > > is watching, and you have to be careful not to spawn to many processes and > > bring the system down. > > I tried this on the system here, but it killed off the process when I > logged off. > > As for starting too many processes, just don't start them... leave it > as one single process that just repeats itself indefinently with sleeps > in between. > Did the processes get killed BECAUSE you logged off ? Or did they get killed because you left a single process runnning in the background for an extended period of time and an automated script killed the job. Why not ask the sysadmin how to setup a long computational job for a couple of days ? I don't think any sysadmin would have a problem with that. Then you could find out if the jobs are killed automatically somehow. If it turns out that it was just the process that was automatically killed on a time interval, then you could easily write a script that would spawn a new process and then kill the parent. Matt

2 1