April 1993 - cypherpunks-legacy

Re: True Randoms
by tcmay＠netcom.com 20 Apr '93

20 Apr '93

William Kinney writes: >A little nuclear physics anyone? > >Seems like one real bitch with roll-your-own cryptography is the >scarcity of good random numbers to work with. I've read about various >schemes using I/O buffers, or keystroke timing like PGP does (even >there, true randoms are referred to as "precious"). > >So I thought a bit about how one could construct a true random generating >box. Went out to Sears and bought a $7 smoke detector, a "Family Gard" > >Does anyone see a real need for something like this? >Any hardware jocks out there who could lend some expertise? What follows is my standard "alpha particles as sources of random numbers" posting, which I have forwarded to the list a couple of times. (I'm not being at all critical of William Kinney for raising the issue again.) Quick summary: thermal noise in a back-biased diode is easier to get, has more bandwidth, doesn't have safety concerns, and is readily buildable. From: tcmay (Timothy C. May) Message-Id: <9210260530.AA00679(a)netcom2.netcom.com> Subject: Alpha Particles and One Time Pads To: cypherpunks(a)toad.com Date: Sun, 25 Oct 92 22:30:54 PDT Cc: tcmay (Timothy C. May) X-Mailer: ELM [version 2.3 PL11] Fellow Cypherpunks, Here's a posting I just sent to sci.crypt, dealing with using alpha particle sources as noise sources for generating one-time pads. Ordinarily I wouldn't bother you folks with this, especially since you're all reading sci.crypt (aren't you? Only the FidoNetters have a good excuse not to.). But this thread ties together two aspects of my life, cryptography and alpha particle errors in chips. --Tim Newsgroups: sci.crypt Path: netcom.com!tcmay From: tcmay(a)netcom.com (Timothy C. May) Subject: Re: Hardware random number generators compatible with PCs? Message-ID: <1992Oct26.051612.29869(a)netcom.com> Organization: Netcom - Online Communication Services (408 241-9760 guest) X-Newsreader: Tin 1.1 PL5 References: <1992Oct25.224554.1853(a)fasttech.com> Date: Mon, 26 Oct 1992 05:16:12 GMT Bohdan Tashchuk (zeke(a)fasttech.com) wrote: : The recent post on building a random number generator using a zener diode got : me to thinking once again about commercial alternatives. : : I haven't seen any commercial alternatives discussed here recently. And since : the market is so specialized, they may well exist but I'm simply not aware of : them. : : The ideal product would have the following features: : : * cost less than $100 : * use a radioactive Alpha ray emitter as the source It's a small world! In my earlier incarnation as a physicist for Intel, I discovered the alpha particle "soft error" effect in memory chips. By 1976 chips, especially dynamic RAMs, were storing less than half a million electrons as the difference between a "1" and a "0". A several MeV alpha could generate more than a million electron-hole pairs, thus flipping some bits. (Obviously the effect of alphas on particle detectors was known, and smoke detectors were in wide use, but nobody prior to 1977 knew that memory bits could be flipped by alphas, coming from uranium and thorium in the package materials. It's a long story, so I won't say any more about it here.) : * connect to an IBM PC serial or parallel port : * be "dongle" sized, ie be able to plug directly onto the port, and : not have a cable from an external box to the port : * be powered directly from the port : * generate at least 1000 "highly random" bits per second This should be feasible by placing a small (sub-microcurie) amount of Americium-241 on a small DRAM chip that is known to be alpha-sensitive (and not all of them are, due to processing tricks). Errors would occur at random intervals, depending on which bits got hit. Getting 1000 errors a second would be tough, though, as such high intensities would also tend to eventually destroy the chip (through longterm damage to the silicon, threshold voltage shifts, etc.). If you really want to pursue this seriously, I can help with the calculations, etc. : Details: : : Certainly in high volume these things can be made cheaply. Smoke detectors : often sell for under $10, and have a radioactive source, an IC, a case, etc. Yes, but smoke detectors use ionization in a chamber (the smoke from a fire makes ionization easier). That is, no real ICs. But ICs, and even RAM chips, are cheap, so your $10 figure is almost certainly in the ballpark. A bigger concern is safety, or the _perceived_ safety. Smoke detectors have, I understand, moved away from alpha particle-based detectors to photoelectric detectors (smoke obscures beam of light). Don't underestimate the public's fear of radioactivity, even at low levels. : Using a well-designed circuit based on Alpha decay should mean that the : randomness is pretty darn good. But not necessarily any better than noise from a Zener. With the higher bit rate from diode noise, more statistical tricks can be done. The relatively low bit rate from alpha decay gives less flexibility. On the other hand, alpha hits are undeniably quite random, with essentially no way to skew the odds (unlike with diode noise). : Everyone these days has either a serial or parallel port available, either : directly or thru a switch box. : : The tiny "dongle" size is a convenience. If it is small and powered directly : from the port, there are no cables to get in the way. There is enough power : available from the signal lines on these ports to power simple devices. E.g. : most mice don't require an external power supply. : : For most applications 1000 bits per second should be adequate. For example, : it would be quite adequate for session keys. For generating pseudo : one-time-pads, an overnight run should generate plenty of values. Continuously : generating values for a month would produce about 300 MB, which should be : enough to exchange new CD-ROM key disks once a month. One time pads are complicated to use. Only very high security applications that can also afford them use them. For example, some diplomatic traffic. I can't conceive of a case where 300 MB a month could be used. And _theft_ (or copying) of the CD-ROM one time pads has got to be a much bigger issue that whether alpha particle noise sources are better than diode noise sources! By about 10 orders of magnitude I would say. Black bag jobs on the sites holding the keys will be the likeliest attack, not trying to analyze how random the noise is (even a fairly crummy noise source will not yield enough information to a cryptanalyst trying to break a one-time pad). Having said all this, I'm glad you gave some thought to alphas. For a time in the late 1970s this was the chip industry's number one headache...it was definitely the most exciting time of my life. --Tim -- .......................................................................... 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 | PGP 2.0 and MailSafe keys by arrangement.

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Sound bite time
by peb＠PROCASE.COM 20 Apr '93

20 Apr '93

Okay, here are my sound bytes: 1. The long one (needed when they try to outlaw encryption): As we move into the electronic frontier, the freedom to use crypto-privacy technology is becoming the equivalent to the right to bear arms: it is the last line of defense against a tyrannic government. The good news is that privacy is a defensive technology, not an offensive one. Giving up this un-enumerated right could be disasterous to future generations. 2. The short one (simple-minded Clipper is no good): Crypto Privacy is like a bullet proof vest for your transmitted speech; the Clipper chip is a paper jacket with extra zippers in the back. Paul E. Baclace peb(a)procase.com

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Subscribe me
by Kang Meng Chow 20 Apr '93

20 Apr '93

SUBSCRIBE ME

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The Wing-Clipper
by fnerd＠smds.com 20 Apr '93

20 Apr '93

> Matthew Lyle (214) 888-0474 > OpenConnect Systems matt(a)oc.com > Dallas, TX > > "...and once you have tasted flight, you will walk the earth with your > eyes turned skyward, for there you have been, and there you long > to return..." It's the Wing-Clipper chip. Great emblem: a bald eagle with its wings clipped. -fnerd quote me

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Re: Mailing list name
by peb＠PROCASE.COM 20 Apr '93

20 Apr '93

I vote for cryptoprivacy because it is more appropriate, and due to recent events, it helps to be clear about these things when the media gets involved. Examples: 1. The infamous CBS coverage of the Hacker's Conference that turned "Cracker" Conference in the nightly news regardless of what the reporters were told. 2. Notice how the NIST press release said ``This system is more secure than many other voice encryption systems readily available today. [^^^^^^^^^^^^^^^^^^^^^^ not claiming the best] While the algorithm will remain classified to protect the security of the key escrow.'' but the Knight-Ridder translated this into: ``...National Security Agency invented a new coding device, called the "Clipper Chip," which is said to be much harder to crack than encoding systems now on the market. Now the wiretap chip sounds better than any equipment on the market rather than "better than many" which is a very weak claim. Happens all the time. Information must be very clear. Punk isn't the right word. Paul E. Baclace peb(a)procase.com

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Let's see here ...
by fergp＠sytex.com 20 Apr '93

20 Apr '93

Once again, I pull together my collective thoughts (that _was_ rather difficult) and send them along for the remainder of the cypherpunks to ponder. It would appear that several things have happened; let's see if I can summarize - - The Clinton administration was presented with a golly-gee proposal from either the NSA or the NIST (probably both) on a way to "offer" public encryption. ('Nuf said.) - From what we have surmised (researched, hypothesized and down-right taken for face value), the government (whether it be the NIST or whomever) has obviously been working on this "technology" for a few years. Albeit, their negligence to inform anyone. - Mr. Clinton and crew obligingly acknowledge this new, technological wonder, and think that they're doing us all a favor. - Enter the "Clipper Chip", and all it's fanfare. Okay. I took The Dark One's advice (not that I needed the prodding, mind you) and faxed every one of the contacts on the list that he posted earlier (a couple of which were voice numbers, BTW). The big three (ABC, NBC and CBS + CNN) got my fax and my thoughts on the subject. I'm mad as hell, too -- yet I'm more prone to bringing this highly volatile subject (it would seem that it's only an explosive situation to those of us who understand it's implications) into the public eye. Let's put this topic into proper prospective -- for the layman, for the "man in the streets." Let me try to put this into prospective for some of our less politically inclined participants. For those of you who live within earshot of the "Beltway", you are probably familiar with the G. Gordon Liddy radio show. Well, to make a long story short, one afternoon the topic was computer crime. A young man called in to express his concern with the topic of "underground" computer virus distribution and all that rot. He was talking on a deaf ear, folks. The program was dominated by yuppies, calling in worried about their precious credit records and how they could possibly be disclosed or damaged by the computer criminals. I turned off the show in disgust at that point, but the point is this: No matter how hard you attempt to bring matters into the light that the _computer_ public should be concerned about, they revert into their own realm of protected computerdom. This is an observation, not a conviction. What we need to do, is to make folks understand that this is not just a computer issue -- it's privacy issue, for cryin' out loud! If the techno-fascists within certain levels of government service think that they can _impose_ their will on the computer community at large, they are most definately ill-informed. Most would probably think that they could fluff this little tidbit of "legislation" into reality. Bottom line: I stand by the ideals that we have every right, as common citizens, to encrypt and cipher as we see fit. Legality be damned. (This is not a legality issue, for christ's sake!) This is an issue where the government is playing bully and we find ourselves on the receiving end of their quest for superiority. I urge each and every one of you to take the time to write your congressman, fax the closest televison or radio station and make this topic as public as possible! I refuse to be treated like a criminal because I desire electronic privacy. Say "No". Cheers. Oh. By the way, I'm looking for some kind sort to offer an avenue to place Legal Net News on an archive site on a regular basis. I find it extremely difficult to meet subscription requests and would prefer to offer this compilation as an anon FTP'able newsletter. Any takers? Issue 2 has bee released, which covers our recent travails .... Paul Ferguson | Uncle Sam wants to read Network Integration Consultant | your e-mail... Alexandria, Virginia USA | Just say "NO" to the Clipper fergp(a)sytex.com | Chip...

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Unsubscribe
by Nathan Rorvig 20 Apr '93

20 Apr '93

Please, unsubsribe me now. Thanks. The mail volume is way to much.

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Subscribing
by greg＠amex-trs.com 20 Apr '93

20 Apr '93

Hello, Please add me to your list of subscribers. Thanks. Greg Thompson greg(a)amex-trs.com

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send info
by cburian＠uiuc.edu 20 Apr '93

20 Apr '93

send info #or, if you're human, _please_ send info on how to subscribe & send the FAQ. #Thanks, Chris Burian -------------------------------------------------------------------------- | Chris Burian | PGP public key available on a server near you | -------------------------------------------------------------------------- <cburian(a)uiuc.edu> <NeXT: cburian(a)sumter.cso.uiuc.edu>

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True Randoms
by KINNEY WILLIAM H 19 Apr '93

19 Apr '93

A little nuclear physics anyone? Seems like one real bitch with roll-your-own cryptography is the scarcity of good random numbers to work with. I've read about various schemes using I/O buffers, or keystroke timing like PGP does (even there, true randoms are referred to as "precious"). So I thought a bit about how one could construct a true random generating box. Went out to Sears and bought a $7 smoke detector, a "Family Gard" model FG888D, and took it apart. What's inside is a 1.0 microCurie chunk of Americium 241 (I checked other models, and they seem to all be AM241, right around the 1 uCi activity range, although I have an older one at home with 5.0 uCi). I did a little research on the isotope in the CRC Handbook and the Brookhaven National Lab's online database, and what I found was pretty interesting: About AM241: Half-Life: 458 years Decay: AM241 ---> (Neptunium 237) + (5.5 MeV alpha particle) 1.0 uCi = 37,000 decays/second average NP237 has a half-life of around 2 million years This is very good design. AM241 has only one basic decay mode, and it decays to an essentially inert daughter product without any intermediate daughters to worry about. Very simple and safe. In addition, the 1.0 uCi activity of the sample makes the decay rate just right for counting alphas with electronic devices -- a 100 KHz sample rate would be overkill for resolving individual alphas. And the half-life is long enough to make the source relatively stable over a reasonable period of use. I took my sample into the lab and it barely registered on the geiger counter, but when I set it up on a scintillating detector, I got about 1200 counts/sec above a background of 25 count/sec. A nice clear signal. Seems to me it would be pretty easy to buy a small solid-state detector and a couple of chips and wire it up to toggle a pin on an RS232 cable, giving a nice true random source -- for instance, assuming the 1200 counts/sec rate I saw in the lab, you could count alphas for 10 milliseconds and send a 1 down the cable if you saw an odd number, a 0 if you saw an even number. Could probably do better than 1200 /sec, too, I bet. Does anyone see a real need for something like this? Any hardware jocks out there who could lend some expertise? Radiological safety data (permissible quarterly intake): AM241 (oral): 7.6 uCi AM241 (inhalation): 3.8E-03 uCi NP237 (oral): 6.2 uCi NP 237 (inhalation): 2.5E-03 uCi In other words, whatever you do, don't smoke it... -- Will

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