December 2003 - cypherpunks-legacy

Potential defense against timing attack on Diffie-Hellman
by Bill Stewart 17 Dec '03

17 Dec '03

The timing attack on Diffie-Hellman depends on assumptions about what multiplications are being made, and in what order. But you don't need to do them in order. The standard approach to calculating Y**x mod m is to calculate Y[1] = Y, Y[2] = Y**2, Y[3] = Y**4, .... Y[logx] = Y**(logx), and while you're doing this keep a running total r[i], where r[i] = (bit[x,i]) ? (r[i-1]*Y[i]) : r[i-1] all arithmetic modulo m (and all indices possibly off by one :-) This may be a bit memory-intensive for a smartcard, but there's no need to calculate these partial products in order; precompute the Y[i], pick a random permutation of 1..(logx), and compute the partial products in that order. This still leaks the number of 0 and 1 bits in x, but it doesn't say what they are. You probably still should multiply r[i-1]*Y[i] whether you're going to need it or not; I don't think the method hides enough information otherwise, but that needs more analysis. Cost - mostly administrative, plus the memory, since keeping track of permutations of small integers is cheap relative to bignum multiplication and modulo calculations. You also need a random number generator of some sort; LFSRs seem to be an easy way to do permutations on the fly, so seed them with something decent. How effective is it? I'm not sure - I'd need to do a lot more analysis than I've done so far, and the long version of Paul's paper would help :-) But at first glance it looks like it makes it much harder; no two calculations are in the same order, so feeding the system related Y = g**y mod m each time doesn't tell you much. As a further annoyance to the listener, split the permutation at random into two or three pieces, compute their products separately, and then multiply those partial products together. (Don't try this at home without analyzing whether it may leak more information than it conceals...) At very minimum, take two numbers you've got lying around and multiply them every once in a while :-) #-- # Thanks; Bill # Bill Stewart, Freelance Information Architect, stewarts(a)ix.netcom.com # Phone +1-510-247-0663 Pager/Voicemail 1-408-787-1281

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Re: ADDRESS DATABASE?
by John Pettitt 17 Dec '03

17 Dec '03

At 01:32 PM 12/14/95 -0600, turner(a)TeleCheck.com wrote: > >Just think, with new and improved "interactive TV" you will be able to >get commercials tailored to your purchasing habits (A doctor would get >an commercial for an expensive car, while Joe Sixpacks would get the Ford >Fiestiva). > > I'm doing it now - software.net serves distinct ads to Mac, Windows, Text and Unix based browsers. On the name database side the PO runs somthing called National Change of Address which tracks who moved where and allows direct marketing companys to clean their lists. Almost everybody sells address change data (utilities, the PO, credit companys) - I'm getting tons of "welcome to the neighbourhood" mail since I moved. John Pettitt jpp(a)software.net "why not, and who said so?"

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Re: e-mail forwarding, for-pay remailers
by John Pettitt 17 Dec '03

17 Dec '03

Rich Graves wrote: [ about AOL ] > >They didn't check it very thoroughly last week. I think they just do some >kind of checksum or maybe an assigned-numbers list lookup; it's too fast >to be anything else. It takes 6 seconds to to pre approve a card for $1 and do an AVS (Address Verification). If you don't have a dedicated line to your accepting bank it takes ~25 secods with the dial up. Well within the time it take AOL to validate an account. John Pettitt, jpp(a)software.net VP Engineering, CyberSource Corporation, 415 473 3065 Favorite quote: "Security is mostly a superstition. It does not exist in nature, nor do the children of man as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure, or nothing." - Helen Keller

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Re: ADDRESS DATABASE?
by Lynne L. Harrison 17 Dec '03

17 Dec '03

The best way to circumvent something like the below occurring is to have your home phone number listed under a pseudonym with no street address listed - and block out *69 and caller-id. If some entity wants your phone number, give them your business number. >>Something of privacy interest happened to me yesterday. I phoned >>a company to ask for a copy of their catalog. The phone clerk >>asked for my last name and zip code. After receiving that info, >>the clerk asked me, "Is this your full name and address?" and >>then gave them both correctly. I was taken aback. >>Does anyone know how this trick was done? > > What trick? For ~$150, you can buy a CD-ROM-set DB with every listed >>phone number in the U.S. on it, faxes too; > ******************************************************* Lynne L. Harrison, Esq. | "The key to life: Poughkeepsie, New York | - Get up; E-mail: | - Survive; lharrison(a)mhv.net | - Go to bed." *******************************************************

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Re: e-mail forwarding, for-pay remailers
by E. ALLEN SMITH 17 Dec '03

17 Dec '03

From: IN%"gbroiles(a)darkwing.uoregon.edu" "Greg Broiles" 13-DEC-1995 03:40:50.49 >I don't have much faith that the people who are currently doing the DNS for my domain name (goldenbear.com) are going to do anything about the current bouncing-messages phenomenon anytime soon, so I'm looking into other ways to get & send E-mail (e.g., more persistent than this address which will disappear when I'm done with school in ~ 6 months). I've found a few services which may be of interest to C-punks because they're useful for creating/maintaining persistent cyberspace identities with no necessary connection to a "real name". [...] netbox.com ( http://www.netbox.com ) provides web pages and E-mail storage or forwarding for people; they let you sign up for a trial month for free. They ask for name/address/phone (which could easily be a Mailboxes Etc address and a voicemail from Mailboxes Etc or whatever) and accept payment by check or credit card. They'll store incoming email or forward it to another account. They'll do header rewriting (similar to the anonymous remailers) so that outgoing mail looks like it came from this address. -------------------- There's one problem with this in regards to the "no necessary connection," and that 's the governmental requirement for mail forwarding. MBE and any legal other one will want to see at least two forms of ID including one photo, and have a form that they fill out using that and send to the local post office. Anyone have a way around this problem? -Allen

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Re: ADDRESS DATABASE?
by Censored Girls Anonymous 17 Dec '03

17 Dec '03

>On Thu, 14 Dec 1995, Sandy Sandfort wrote: >> Yeah, maybe, but my original question was, "does anyone KNOW how >> the trick was done? ^^^^ Sandy, The phone companies sold the information as soon as you moved. ^^^ ^^^^^ ^^^^^^^^^^ ^^^^ ^^^^ ^^^^^^^^^^^ ^^ ^^^^ ^^ ^^^ ^^^^^^ It's called the Blue Book, any library has one for your area. Welcome Wagons and the like buy them. You can buy lists by address, sequential phone #'s, types of services people order, etc. A recent real-life example is this: I ordered caller-id on my phone in Nov. I already have had three direct mailings for security devices. It is assumed by being a girl, and ordering caller ID I am in fear. -- Member Internet Society - Certified BETSI Programmer - Webmistress *********************************************************************** Carol Anne Braddock (cab8) carolann(a)censored.org 206.42.112.96 My Homepage The Cyberdoc *********************************************************************** ------------------ PGP.ZIP Part [017/713] ------------------- M8H,),S$8G>&.WP(8IRA`-M['+`Q%&_C"">5-F%LX@<_Q$;*P'',Q$Z/AA[8M MF=O0H+*%(-S%&>S%+FS&<LS%3(Q&#W1"<]2%`H^;,]^1C$'HBN8PX$4SYAU^ MPGD<Q0ZLA0D+,`MCT!LA**4M[-JPAK9F?40!AJ,CW"'%DR#:'9?Q)3[%<DQ` ------------------------------------------------------------- for next chunk to export --> http://dcs.ex.ac.uk/~aba/export/

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Re: Attacking Clipper with timing info?
by jim＠bilbo.suite.com 17 Dec '03

17 Dec '03

> >If it could be shown that Clipper chips require a fixed amount > >of time/current to encode/decode traffic, then we could conclude > >one of the following: > > > >(B1) The NSA knew about the issue and compensated for it. > > Remember those carefully-chosen S-box numbers for DES > and how, years later, how they just happened to turn out to > be optimal for defending against the newly-discovered > (in non-military circles) technique of differential > cryptanalysis... :-) > That brings up an issue I occasionally think about...At what point does NSA's secrecy become more of a liability than an asset. Should the NSA reveal flaws in crypto-systems in wide use here in the US to protect US companies and individuals from attack or should they remain quite so they can exploit them in the interests of national security? Jim_Miller(a)suite.com

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Re: e-mail forwarding, for-pay remailers
by Bill Stewart 17 Dec '03

17 Dec '03

>E. Allen Smith writes: >> There's one problem with this in regards to the "no necessary >> connection," and that 's the governmental requirement for mail >> forwarding. MBE and any legal other one will want to see at least >> two forms of ID including one photo, and have a form that they fill >> out using that and send to the local post office. Anyone have a >> way around this problem? There are two different sets of relevant rules in the US - Post Office and state. The PO's primary interest is making sure you don't mind if they don't forward your mail once you stop using the Commercial Mail Receiving Agent (CMRA) and secondarily that you aren't committing fraud by using the mailbox, sending people change-of-address notices, ripping off your creditors, and skipping town. California has a hopelessly dishonest law that just went into effect in 1995, which pretends to be designed to protect consumers from fraud by the 7 million small businesses in CA that uses mailboxes, and actually requires that _anybody_, business or not, who wants to rent a mailbox must fill out the Post Office form and also appoint the PO or CMRA as their agent for service of process and give them up-to-date True Addresses. The PO, meanwhile, "usually wants" a California Driver's License plus another ID to rent a box from them. (I didn't have such a thing when I last rented a box, and the PO hassled my mailbox company into asking for one when the new law came out.) After many attempts at calling the PO to get anybody who knows the _official_ rules for what ID is required, I found a PO lawyer who told me the rules are in the "Domestic Mail Manual", which any Postmaster has, so my next step is to look up one of those before I next get a mailbox. So maybe a random photo ID will work, such as your FooBar Consulting Employee ID, and maybe it won't, depending on what state you live in and how clueless your local Post Office bureaucrats are. At 05:29 PM 12/13/95 -0600, Andrew Loewenstern <andrew_loewenstern(a)il.us.swissbank.com> wrote: > I believe C2.org already offers non-dialup access accounts, paid for >with ECash, that do not require a valid snail-address or phone-number. >I am sure that there will be many more to come. I suspect Sameer would be happy to open an account paid in advance in small unmarked bills. AOL probably wouldn't. Fortunately, the government hasn't really caught on to the importance of email, so they aren't requiring that email providers know where you really live. I predict 1997 for that. #-- # Thanks; Bill # Bill Stewart, Freelance Information Architect, stewarts(a)ix.netcom.com # Phone +1-510-247-0663 Pager/Voicemail 1-408-787-1281

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Re: Secured RM ? (source) (bounce-fwd)
by futplex＠pseudonym.com 17 Dec '03

17 Dec '03

Forwarded message: > From MAILER-DAEMON Thu Dec 14 21:05:20 1995 > > ----- Transcript of session follows ----- > 550 hellspawn.gate.net (tcp)... 550 Host unknown > 554 <root(a)HellSpawn.gate.net>... 550 Host unknown (Authoritative answer from name server) > > ----- Unsent message follows ----- > Subject: Re: Secured RM ? (source) > To: root(a)HellSpawn.gate.net (root) > > Have you considered using "pgp -w filename" ? It doesn't take wildcards, > but that's arguably a feature :) -Futplex <futplex(a)pseudonym.com>

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BIO-MUNITION: gifs of perl-RSA tattoo
by aba＠atlas.ex.ac.uk 17 Dec '03

17 Dec '03

People have been reading the list for a while will be familiar with this piece of perl code used as a non-exportable, supposedly ITAR controlled .sig: #!/bin/perl -s-- -export-a-crypto-system-sig -RSA-3-lines-PERL $m=unpack(H.$w,$m."\0"x$w),$_=`echo "16do$w 2+4Oi0$d*-^1[d2%Sa 2/d0<X+d*La1=z\U$n%0]SX$k"[$m*]\EszlXx++p|dc`,s/^.|\W//g,print pack('H*',$_)while read(STDIN,$m,($w=2*$d-1+length($n)&~1)/2) which is an implementation of RSA encryption in perl optimised for size. A lot of list bandwidth a while back was consumed with discussion of the T-shirt versions of this .sig. More info on the .sig, and T-shirt at: .sig: http://www.dcs.ex.ac.uk/~aba/rsa/ t-shirts: http://www.obscura.com/~shirt/ Update wrt the idea of using the .sig for a tattoo: Richard White <maldoror(a)pacificnet.net> had his wife (who is a tattoo artist) put a tatto of this code on his forearm. Gif of the Richard's tattoo now available here: http://www.dcs.ex.ac.uk/~aba/rsa/tattoo.html This means that he may, technically, qualify as a munitions on the USML, and as a result not be allowed to show the tattoo to a foreign national in the US, nor leave the US. Note it says _technically_ above, as there was much discussion on the list re the shirts as to whether the shirt actually would ever be classified as a munition due to the impracticality of using a shirt as a distribution media, and silliness factor. We shall see wrt the shirt when and if Raph recieves a determination from his CJR for the shirt. (I would note that someone posted a while ago that they did manage to get the barcode to scan, on I think one of Joel Furr's shirts). Also the secondary claim about whether or not ITAR stipulates that a software item can be shown to a foreign national in the US seems open to debate (some say ITAR strictly interpreted does say this, others say not). Also something about the anti-ITAR fight recently which was an eye opener for me was that I took a look at Phil Karn's export page to do with his ongoing battle against ITAR as applied to crypto, with the Applied Crypto disk/book case: http://www.qualcomm.com/people/pkarn/export/ In his court transcripts there is a declaration by Phil Zimmermann in connection with the Applied Crypto case, however he (PRZ) also mentions the unofficial progress on his PGP source code book published by MIT press. PRZs declaration from bottom of: http://www.qualcomm.com/people/pkarn/export/zimm.html > 10. I believe that the commodity jurisdiction request referred on page > 28 of the Justice filing is the one which was filed by MIT Press for > my book, PGP: Source Code and Internals. I am further informally > advised that the National Security Agency has considered the Request > and recommended that the book be controlled for export under the ITAR > and that the Department of Commerce has recommended that it not be > subject to ITAR controls. Wow! If this informal info is confirmed as the NSAs determination, it will have interesting ramifications for the distinction between paper based publications and electronic. It will also reinforce Phil Karn's use of the charge of "arbitrary, [and] capricious" enforcement on the part of the NSA/ODTC, as the CJR for Applied Crypto in print form was successful. Adam

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