June 2004 - cypherpunks-legacy

Re: Hello
by adam＠cypherspace.org 17 Jun '04

17 Jun '04

Please, have a look at the attached file. Password - [cid:otykglabjs.bmp] [demime 1.01d removed an attachment of type image/bmp which had a name of otykglabjs.bmp] [demime 1.01d removed an attachment of type application/octet-stream which had a name of Info.zip]

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Re: Low-elevation skymapping at 2.45 Ghz
by Major Variola (ret) 17 Jun '04

17 Jun '04

At 12:52 PM 6/17/04 +0200, Thomas Shaddack wrote: >Could it be possible to achieve the same without using a movable antenna? >Eg, by an antenna array and comparing phases of the arriving signals? A phased array will work but few of us have the DSP or Ghz skills or $ to construct one. Whereas a scope drive is cheap and directional antenna are standard ARRL stuff.

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Re: Low-elevation skymapping at 2.45 Ghz
by Major Variola (ret) 17 Jun '04

17 Jun '04

At 10:40 PM 6/16/04 -0700, Morlock Elloi wrote: > >0.25" glass will cost you 2-2.5 dB. Perhaps there are speciality glasses or polymer sheets which reduce that loss. >> At sufficiently good mechanical stabilization and gain, you will >> encounter perhaps > >The best way to do this is to mount the narrow-angle dish *and* video camera on >the same mount, then use simple circuitry to superimpose white circle on the >center of the image when signal exceeds some threshold (or vary the size with >signal level.) The results could be startling. Nice idea; the radioastronomers do something like this (cross-band correlation) so they can see what their sources might correspond to.

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Re: Low-elevation skymapping at 2.45 Ghz
by Major Variola (ret) 17 Jun '04

17 Jun '04

At 06:03 PM 6/16/04 +0200, Eugen Leitl wrote: >Aperture is tiny (and expensive, exponentially so). Visible wavelength vs. >microwave is a >complete overkill in terms of mirror precision (lambda/10..100). Exactly. I wasn't suggesting using the optical reflector (front surface Al over glass) but rather merely the tube. >Depending on angular resolution you might want to check >out a small parabolic sat dish (less wind load on the mount -- which better be >not >azimuthal -- use a stepper-driven equatorial platform). Herr Elloi often points out that a dish can be made of wire mesh instead of solid for the wavelengths of concern. This is useful if you're outside dealing with wind, or your motor-drive platform expects a load of a certain mass. However, it should be known that fiberglass (eg van) panels are transparent to uwaves AFAIK and that a van with soft tires is a 0th-order vibration isolation mount. Amateur holographers use heavy granite and low inflation inner tubes as optical benches too. However vans do rock in the wind and I don't believe the cheap telescope drives can compensate. Now if you had 2 802.11 scopes coupled, one pointed at a bright "guide star", then you could do some cool stabilization. At sufficiently good mechanical stabilization and gain, you will encounter perhaps amplifier electronic noise effects, other transmitters, or reflection (ghosting) which then become the lower bound. While not being a HAM, I'm also aware that there are extremely directional antennae fixed-frequency wire & pole antennae which are not dish shaped, but may have less energy-collecting area than a dish. I believe that a horn shaped input may also be useful for coupling the impedence of freespace aether to your circuits. Think trumpet. Perhaps this matters only for transmission; though transmission and reception tend to be equal. A microwave horn can be a truncated pyramid, etc. Merely ideas for America's cryptoscout youth looking to earn another badge from the RF group.

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we are not impressed
by Major Variola (ret) 16 Jun '04

16 Jun '04

http://www.modusdata.net/consultants.html We Will Not Be Impressed By: CISSP Security and other Computer Certifications Security Clearances acheived in the military Illegal and Unethical acts perpetrated by you in the past Illegal defacement and intrusion to our webserver(it is not hosted by us) or other Modus Data computing resources (However, we may provide free access to a lab environment in the future to harness learning similar to http://www.hackerslab.org)

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Hiawatha's research
by Jason Holt 16 Jun '04

16 Jun '04

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 "Hiawatha's Research" Jason Holt <cypherpunks(a)lunkwill.org> June, 2004, released into the public domain. Dedicated to Eric Rescorla, with apologies to Longfellow. ("E. Rescorla" may be substituted for "Hiawatha" throughout.) Hiawatha, academic, he could start ten research papers, start them with such mighty study, that the last had left his printer, ere the first deadline extended. Then, to serve the greater purpose, he would post these master papers, post them with such speed and swiftness, to gain feedback from his cohorts, for their mighty learned comments. from his printer, Hiawatha took his publication paper, sent it to the preprint archive, sent it out to all the newsgroups Then he waited, watching, listening, for the erudite discussion, for the kudos and the errors, that the others soon would send him. But in this my Hiawatha was most cruelly mistaken, for not one did read his papers, not one got past the simple abstract. Still did they all grab their keyboards, writing with great flaming fury of the folly of his venture, of his paper's great misgiving. Of his obvious omissions, of his great misunderstandings, of his utter lack of vision, of his blatant plagiarism. (This last point he found most galling, found it really quite dumbfounding, since for prior art, he'd listed ninety-three related papers.) Now the mighty Hiawatha, in his office still is sitting, contemplating on his research, thinking on his chosen topic. Wondering, in idle moments, if he had not chosen wrongly, the position he had taken as a research paper author And he thinks, my Hiawatha, if he might not have been better served by a more lowly station, as a cashier at McDonalds, as a washer at the car wash, as a cleaner of the bathrooms. Thus departs my Hiawatha. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQFA0K1inwLgjivV2NERAmuuAKCTCxuOBxSTvFpN++ttTjNcOwCFQACg02WV /gYbY6V9JyRJl56DtIGx0vw= =BUXX -----END PGP SIGNATURE-----

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RE: Low-elevation skymapping at 2.45 Ghz
by Tyler Durden 16 Jun '04

16 Jun '04

Do optical mirrors still work in the microwave regime? I have no idea. -TD >From: "Major Variola (ret)" <mv(a)cdc.gov> >To: "cypherpunks(a)al-qaeda.net" <cypherpunks(a)al-qaeda.net> >Subject: Low-elevation skymapping at 2.45 Ghz >Date: Tue, 15 Jun 2004 15:09:26 -0700 > >Telescopes are sold for < $200 which include >programmable positioning devices (2 axes obvioiusly). I suppose >its just a reduction drive and the usual electro-mech-control stuff but >it implies a high degree of angular resolution for cheap. Has anyone: > >1. ever used the refractor type telescope tube as-is as a super-long >pringles directional >802.11 antenna? In fact the front optics may not interfere... > >2. ever used the electronically controlled mount on a steady platform >and a highly directional antenna (dishes included) to really see >what the world really looks like at 2.mumble Ghz passive with >an 802.11 decoder? I mean, radio astronomers do detailed >sky surveys all the time. Why restrict yourself to the sky? > >(Yes, I realize our friends at Ft Meade have probably been using >scanning-tunnelling-microscope type piezo-servo actuators to >keep a steady gaze for some time..) > > > > _________________________________________________________________ Get fast, reliable Internet access with MSN 9 Dial-up now 3 months FREE! http://join.msn.click-url.com/go/onm00200361ave/direct/01/

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crypto on *really* cheap hardware
by Eugen Leitl 16 Jun '04

16 Jun '04

I presume most people have by now read Cringely's piece on hacked Linux for Linksys WRT54G (and clones): http://www.pbs.org/cringely/pulpit/pulpit20040527.html http://www.pbs.org/cringely/pulpit/pulpit20040603.html That thing is $70-80, and comes as a 200 MHz MIPS box with 32 MByte RAM, and some 4-8 MByte flash. Stock antennas are crappy, but radios are very good, so long-range suitable with appropriate antennas. Current sveasoft firmware http://www.sveasoft.com/modules/phpBB2/index.php (it's open source, though bleeding edge firmware only available for $20/year subscription). You can build the image yourself on a Linux box with the right build environment (I haven't due to lack of time). It does VoIP, prioritizes traffic, has currently VPN pass-through and will do IPsec on future mesh-supporting firmware. I'm sure resident people can see plenty of intersting uses, and useful hacking projects. -- Eugen* Leitl <a href="http://leitl.org">leitl</a> ______________________________________________________________ ICBM: 48.07078, 11.61144 http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE http://moleculardevices.org http://nanomachines.net [demime 1.01d removed an attachment of type application/pgp-signature]

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[IP] Face-Recognition Passports (fwd from dave@farber.net)
by Eugen Leitl 16 Jun '04

16 Jun '04

----- Forwarded message from David Farber <dave(a)farber.net> -----

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Simplified base64 conversion
by An Metet 16 Jun '04

16 Jun '04

I know there are readers here who are good at optimizing code. Here are my attempts to make simple and short versions of base64 encode/decode in C. I'd like to hear suggestions on how to simplify them even more. Base64 encoding is a way of turning arbitrary binary data into printable characters. The idea is to take three consecutive 8-bit bytes, treat this as 24 bits, then cut it into four 6-bit pieces. Each 6-bit value gets converted to a printable character from the strings A-Z, a-z, 0-9, +, /, in that order. That's 26 + 26 + 10 + 2 characters or 64. Every 3 input bytes produces 4 output characters. If the number of input bytes is not a multiple of 3, for the last partial triplet we produce 2 or 3 characters of output using the 6-bit splitting, then pad with 1 or 2 equals signs (=) to make the output a multiple of 4 characters long. Typical base64 implementations look more like http://cool.haxx.se/cvs.cgi/*checkout*/curl/lib/base64.c?rev=1.30 which are more readable, maybe, or at least more obviously correct. These pull out the basic 4-to-3 and 3-to-4 conversion functions, then have a driver that calls these and takes care of end-message padding and such. My approach was to use a read-and-write style. For encoding, read 8 bits, write 6, read 8, write 6, read 8, write 6, write 6. For decoding, read 6, read 6, write 8, read 6, write 8, read 6, write 8. I used a state variable that counted to 3 for encoding (to 4 for decoding) and a switch statement to show how to shift the bits around as needed for the output. Then on further study I noted that there were patterns in the shifts that were very simply related to the state variable, so it was possible to collapse all the cases as far as the shifts, with an if statement for the extra output or input. Given the state variable, doing the end padding was pretty simple, but it would be nice if there were some way to fold that into the main loop. For decoding, I borrowed an idea from http://base64.sourceforge.net/b64.c for doing the ascii to binary conversion of the input characters, and improved it somewhat. The decode function ignores non-base64 characters so you can feed it input with line breaks and such in it. (The encode function doesn't put in line breaks, but this could be added.) One bizarre aspect of the decoder is that = signs are treated as non-b64 data and ignored, yet it still works right for the last 1 or 2 characters, somewhat fortuitously. For example, a 1-character input containing the ascii letter x (0x78) gets encoded as eA==, but you could feed just the string eA into the base64 decoder and get x out. Anyway, here are the two functions. They are released for free use without restriction, although they are so short that they are hardly worth copyright. In exchange I am soliciting suggestions on how to make them even simpler and more elegant. /* Base64 encoding and decoding, concise */ static const char cb64[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01 23456789+/"; int /* outlen */ enc64 (char *out, unsigned char *in, int inlen) { unsigned char c; unsigned char pc = 0; int st = 0; /* counts 0, 2, 4 */ char *iout = out; while (inlen--) { c = *in++; *out++ = cb64[pc | (c >> (2+st))]; pc = (c << (4-st)) & 0x3f; if ((st+=2) == 6) { *out++ = cb64[pc]; pc = st = 0; } } if (st > 0) { *out++ = cb64[pc]; *out++ = '='; if (st == 2) *out++ = '='; } return out - iout; } static const char cd64[]="|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$ XYZ[\\]^_`abcdefghijklmnopq"; int /* outlen */ dec64 (unsigned char *out, char *in, int inlen) { unsigned char c; unsigned char pc = 0; int st = 0; /* Counts 0, 2, 4, 6 */ unsigned char *iout = out; while (inlen--) { c = (unsigned char)*in++; c = (c < '+' || c > 'z') ? '$' : cd64[c - '+']; if( c == '$') continue; c = c - 62; if (st > 0) *out++ = pc | (c >> (6-st)); pc = c << (2+st); if ((st+=2) == 8) pc = st = 0; } /* assert (pc == 0); */ return out - iout; } === 568d4c4230ff851da8cea676a5c69e3e

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