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Time Locks-- Re: Delayed self-encrypting messages
by pcw＠access.digex.net 17 Dec '03

17 Dec '03

>----- Begin Included Message ----- > >>From owner-cypherpunks(a)toad.com Fri Jun 10 15:13 CDT 1994 >Date: Fri, 10 Jun 1994 13:04:07 -0700 >From: Paul Schauble <pls(a)crl.com> >To: Cypherpunks(a)toad.com >Subject: Delayed self-encrypting messages >Precedence: bulk > >I have a need to distribute some information fairly widely, but it's >critical that it not be openly revealed before a certain date. Consider the >model of an embargoed press release. > >Can I do this with crypto technology? Can I send someone a message, and >possible a program, such that the message can only be decrypted after a >predetermined date? > > > > ++PLS > > > >----- End Included Message ----- > >You could do the simple way, distribute the message, then a key at the >later date. To make sure the encrypted message is genuine, sign the message >encrypt it, then sign it again, to ensure that people know that the >encrypted text is okay. This is a good method, but let's say that you die in between? What happens? I wrote a paper on Crypto Time Locks that is a fair to okay solution. It was a loose extension on a scheme from Crypto 92 for reducing Junk Mail. Here's a summary: What you want is an encryption function f and its inverse f' such that computing f' takes some factor of n times longer than f. So if you want to lock things up for 128 days and you're willing to put in 1 day of computation time, then you look for a pair of f and f' such that n=128. One example of such a pair is DES with 48 bits of the key fixed. The locker chooses the extra 8 bits at random. The unlocker tries all 256 combinations until the correct answer is found. Actually, you want to don't want to use DES, you want to use a variant that I'll call k-DES for lack of a better name at this time. k-DES is DES with more than 16 rounds. It is DES with enough rounds to make it run for k units of time on the fastest, commonly available RISC chip. Note that this is an inherently serial computation. A better approach would probably be to use some sort of triple DES variation with more fixed bits to prevent birthday attacks. This simple version is succeptable to attacks by parallel machines. There are better versions that I don't have time to describe at this moment. You can also construct pairs of f and f' using public key functions. When you need to choose one of the two keys, set one to be 3 or 5 or some small number. That means that exponentiation for locking (encryption) will only take log(3) steps. But decryption could take log(X) steps where X is the other key. Note that the "strength" of RSA is not being used in this case. Everyone knows both keys. But decrypting with one is still a factor of n times longer. Copies of the extended paper are available to anyone curious. -Peter Wayner

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Delayed self-encrypting messages
by Paul Schauble 17 Dec '03

17 Dec '03

I have a need to distribute some information fairly widely, but it's critical that it not be openly revealed before a certain date. Consider the model of an embargoed press release. Can I do this with crypto technology? Can I send someone a message, and possible a program, such that the message can only be decrypted after a predetermined date? ++PLS

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Re: DES w/ variable S-boxes
by Ben.Goren＠asu.edu 17 Dec '03

17 Dec '03

At 10:32 PM 6/15/94 -0400, Rick Busdiecker wrote: > Date: Wed, 15 Jun 1994 17:32:24 -0700 > From: Ben.Goren(a)asu.edu > > Are there any implementations of DES-variants that use variable S-boxes? > >Well, if you don't use the DES S-boxes then it isn't DES :-) Well...yeah.... >Variable boxes tend to weaken DES. The DES S-boxes were chosen to >make differential cryptanalysis difficult. Random S-boxes don't tend >to have this desirable property. Perhaps I should clarify: not DES with randomly-chosen fixed S-boxes; I'm well aware that those that DES uses are the best for differential cryptanalysis. However, as Bruce Schneier points out (p. 242), *variable* S-boxes make differential cryptanalysis impossilbe, as such an adaptive plaintext attack relies on knowledge of the composition of the S-boxes. If the boxes and their contents change with both keys used and plaintext--probably with the help of a strong RNG--then the only way such an attack could work would be by first figuring out what causes the changes in the S-boxes; in that case, the attack is probably already finished, by other means. Perhaps, even, the S-boxes could change with so many chunks of text--again, variable, of course. Most, if not all, of the actual S-box designs used would be much weaker than the original design of DES for differential cryptanalysis. However, each different plaintext (and key) would use different s-boxes, so that particular attack isn't possible. So, I guess part of my question should be, does this open up other attacks? Or, for that matter, am I completely wrong? And, like I said before, has this been done? >Use IDEA. Certainly, until there's something better. I'm just hoping this might be, or that I can learn more along the way. > Rick And thanks to Bill and Lyman, who also responded similarly. b& PS Hopefully, I'll learn to check the Cc: line more carefully in the future. Apologies again for the noise. b& -- Ben.Goren(a)asu.edu, Arizona State University School of Music net.proselytizing (write for info): Protect your privacy; oppose Clipper. Voice concern over proposed Internet pricing schemes. Stamp out spamming. Finger ben(a)tux.music.asu.edu for PGP 2.3a public key.

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NetCenter Member Services - VeriSign Digital ID Request
by id-center＠verisign.com 17 Dec '03

17 Dec '03

Dear NetCenter Member: Thank you for requesting information about VeriSign Digital IDs from Netscape's Netcenter. A VeriSign Digital ID provides a means of proving your identity in electronic transactions, much like a driver license or a passport does in face-to-face interactions. By using your Verisign Digital ID you can: *Sign your e-mail. Recipients are assured that the information they receive is from you, and hasn't been altered in any way by outside tampering. *Encrypt and decrypt e-mail. This assures no one except the intended recipient can view its contents. In addition: VeriSign's new public directory is your "white pages" for Digital IDs. Look up anyone's Digital ID. Then send and receive signed and encrypted e-mail -- all from within Netscape Messenger. (If you use another email package you can still easily access the directory from VeriSign's web site.) Your browser will automatically store your Digital ID and present it for you at participating sites. This means no longer remembering multiple passwords to gain access to these sites. You automatically receive the peace-of-mind of US $1,000 NetSure(sm) protection against economic loss caused by corruption, loss or misuse of your Digital ID (not available with free trial ID). For more information about Digital IDs and how they are used, please visit http://www.verisign.com/products/individual/index.html. To enroll for a VeriSign Class 1 Digital ID, please complete the form below, read our Subscriber Agreement, then click the Accept button. If you are not using Netscape Mail, you may not be able to view the form below. Please visit our Digital ID Center at http://digitalid.verisign.com/class1Netscape.htm to enroll for your free Class 1 Digital ID. Title: VeriSign Class 1 Digital ID STEP 1: Contents of Your Digital ID. This information is included in the Digital ID which is available to the public. NOTE: Please complete with no punctuation. Please use only the English alphabet with no accented characters. First name: Last name: Email address: Include email address in your Digital ID? Yes No Answer Yes to use your ID for sending and receiving secure email. STEP 2: Easy Web Site Registration You have the option of including this one-step registration information in your Digital ID (which is also available to the public), in order to use it for "one-step registration" at participating websites and customized information services. Personalize your Digital ID? YesNo Country: Australia Austria Belgium Brazil Canada China Denmark Finland France Germany India Israel Italy Japan Mexico Netherlands Norway Philippines Singapore South Africa Spain Sweden Switzerland Taiwan United Kingdom United States Other Countries Zip or postal code: Date of birth:(MMDDYYYY) (Example: 12251966) Male Female STEP 3: Choose a Challenge Phrase A challenge phrase enables you to cancel and replace your Digital ID (i.e., if you change computers, software, etc). The challenge phrase is only known by you and should be kept in a safe place - you must have it to cancel your Digital ID if it is compromised or stolen. Challenge phrase: No punctuation, please. STEP 4: Choose Full Service Class 1 Digital ID or 60 day Free Trial A full service Digital ID comes with these features: Send and receive secure e-mail (via S/MIME) Replaces passwords and enables one-step registration at participating websites VeriSign Customer Care, 24 hours a day, 7 days a week Automatic Enrollment in $1,000 NetSureSM Protection Plan Free replacement and revocation of your Digital ID should it be lost or corrupted I'd like a full service Digital ID for only US$9.95. (Please complete Step 5.) I'd like to test drive a 60-day trial Digital ID for free. (does not include revocation, replacement, the NetSure Protection Plan or premium customer care) STEP 5: Finalize Enrollment Your Digital ID is valid for a one year period. Your credit card will be charged US$9.95 when you click the Accept button below. All enrollment and credit card information is transmitted securely using the Secure Sockets Layer (SSL) protocol. This information is kept confidential and is not included in your Digital ID. Card type: Visa MasterCard Discover American Express Card number: Expiration date: 01 02 03 04 05 06 07 08 09 10 11 12 97 98 99 00 01 02 Name on card: Street number: Street name: Apt. #: City: State/Province: Zip/Postal Code: Country: Australia Austria Belgium Brazil Canada China Denmark Finland France Germany India Israel Italy Japan Mexico Netherlands Norway South Africa Spain Sweden Switzerland United Kingdom United States Other Countries PLEASE READ THIS SUBSCRIBER AGREEMENT BEFORE APPLYING FOR, ACCEPTING, OR USING A DIGITAL ID/CERTIFICATE. IF YOU DO NOT AGREE TO THE TERMS OF THIS SUBSCRIBER AGREEMENT, PLEASE DO NOT APPLY FOR, ACCEPT, OR USE THE DIGITAL ID (CERTIFICATE). THIS SUBSCRIBER AGREEMENT will become effective on the date you submit the certificate application to the designated issuing authority (IA). By submitting this Subscriber Agreement (and certificate application) you are requesting that the IA issue a Digital ID (certificate) to you and are expressing your agreement to the terms of this Subscriber Agreement. VeriSign's Public Certification Services are governed by VeriSign's Certification Practice Statement (the "CPS") as amended from time to time, which is incorporated by reference into this Subscriber Agreement. The CPS is published on the Internet in VeriSign's repository at https://www.verisign.com/repository and ftp://ftp.verisign.com/repository/CPS and is available via E-mail from: CPS-requests(a)verisign.com. Amendments to the CPS are also posted in VeriSign's repository at https://www.verisign.com/repository/updates. YOU AGREE TO USE THE DIGITAL ID (CERTIFICATE) AND ANY RELATED IA SERVICES ONLY IN ACCORDANCE WITH THE CPS. NETSURE(SM) NOTICE: THE NETSURE(SM) CERTIFICATES ISSUED UNDER THIS AGREEMENT AND OTHER AGREEMENTS AND THEIR EFFECTIVE DATES UNDER THE NETSURE(SM) PROTECTION PLAN ("PLAN") ARE LISTED AT HTTPS://WWW.VERISIGN.COM/REPOSITORY/NSCERTS.HTML. EFFECTIVE MAY 30, 1997, IF YOU OBTAINED A NETSURE(SM) CERTIFICATE, THE PLAN PROVIDES YOU WITH CERTAIN LIMITED WARRANTIES, DISCLAIMS ALL OTHER WARANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, AND LIMITS LIABILITY. FOR INFORMATION ON THE PLAN, SEE HTTPS://WWW.VERISIGN.COM/REPOSITORY/NETSURE. OTHERWISE, THE IA PROVIDES LIMITED WARRANTIES, DISCLAIMS ALL OTHER WARANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, LIMITS LIABILITY, AND EXCLUDES ALL LIABILITY FOR INCIDENTAL, CONSEQUENTIAL, AND PUNITIVE DAMAGES AS STATED IN THE CPS. SEE THE CPS FOR IMPORTANT DETAILS. YOU DEMONSTRATE YOUR KNOWLEDGE AND ACCEPTANCE OF THE TERMS OF THIS SUBSCRIBER AGREEMENT BY EITHER (I) SUBMITTING AN APPLICATION FOR A DIGITAL ID (CERTIFICATE) TO VERISIGN, OR (II) USING THE DIGITAL ID (CERTIFICATE), WHICHEVER OCCURS FIRST. Read CPS or Download CPS If you agree to the terms of the Subscriber Agreement, please click Accept to continue. Optional Enhancement If you use the standard version of Netscape Navigator or Communicator, choose 512 from the list below. If you use the US-only version, you can choose 768 or 1024 for greater security. Copyright © 1997, VeriSign, Inc.

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AUTOPGP 2.1
by bmorris＠netcom.com 17 Dec '03

17 Dec '03

To: cypherpunks(a)toad.com Anyone know a FTP site for AutoPGP 2.1? * RM 1.4 B0037 *

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PGP mailer for Xwindows
by dfloyd＠runner.utsa.edu 17 Dec '03

17 Dec '03

Is there such a thing as a PGP X mailer? Something like mailtool on Suns or MediaMail on SGI's that supports PGP signing/encryption? Thanks in advance,

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Anyone going to Xhibition '94?
by Martin Janzen 17 Dec '03

17 Dec '03

Speaking of physical meetings... The annual X Window System show, Xhibition '94, is at the San Jose Convention Center from June 20-24 this year. Is anyone else from this list planning to attend? If you are, or if you are in the Bay Area already, and would be interested in an informal get-together during that week, send me a note or (on or after the 18th) leave a message at the San Jose Hilton. Maybe we can put together a C-Punks dinner or a pub night or something... -- Martin Janzen janzen(a)idacom.hp.com Pegasus Systems Group c/o Hewlett-Packard, IDACOM Telecom Operation

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Re: Time Locks-- Re: Delayed self-encrypting messages
by dfloyd＠runner.utsa.edu 17 Dec '03

17 Dec '03

(Timelock algorithm deleted) --- That is a good way for locking it up for a while, but if it is really time sensitive, the use of parallel key guessing machines would stick a sock in this method. Here are some (non crypto) alternatives that you can use if you want to delay giving out the key after posting the cyphertext of the message: 1: Give the key to a trusted party, like your attorney to give out. 2: Find some way of getting the key lost via transport via SMTP daemons. If a host gets mail regularly via a UUCP connection, bounce it X times off that host. 3: Get the key "lost" in snail mail by this route. Mail it to a friend or a neutral party (Many copies if you may be snuffed in the process, to many people, and make "smokescreen" mails too). This would only work for messages with a short delay (24-48 hours). 4: (Very farfetched, but I am running out of ideas) Use a laser to bounce the key off a far planet or some body and the light travelling to there and back may give a decent delay. I do not know how you would get a coherent message back though. BTW: The time-lock idea sounds good, the mail list driver echoed it twice :) PS: Anyone have any better ideas for a secure crypto way of doing this? ;)

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Electronic distribution of op-eds from the Competitive Enterprise Institute!
by Competitive Enterprise Institute 17 Dec '03

17 Dec '03

[Please distribute this as widely as you see fit. Thanks. -- Sasha Volokh] The Competitive Enterprise Institute is pleased to announce the CEI list! Established in May, the CEI list already has over 250 subscribers. The CEI list distributes our op-ed pieces, and perhaps other items of interest. To subscribe, drop a note to: Alexander "Sasha" Volokh at cei(a)digex.com But first, a little bit about CEI: "In today's political climate of higher taxes and the expansion of government, the need for free market voices like CEI is critical to the survival of America's free enterprise system." - The Honorable Dick Armey U.S. House of Representatives Founded in March of 1984, the Competitive Enterprise Institute is committed to advancing the principles of free enterprise and limited government. The Institute is founded on the belief that free markets and individual liberty best serve the public interest by providing freedom of choice and equal opportunity. The Institute's articles on key policy issues appear regularly in major media publications such as *The Wall Street Journal*, *The Washington Post*, and *USA Today*. The Institute's analysts also appear on international and national television programs such as *The MacNeil/Lehrer News Hour*, *Good Morning America*, CNN's *Crossfire* and *Larry King Live*. CEI analysts can also be heard on numerous national and local radio shows across the country. The Institute's policy analysts concentrate on the following issue areas: ECONOMIC REGULATION We analyze the human and economic costs of government tax and regulatory policies. ENVIRONMENTAL STUDIES The Institute's work emphasizes the reinstatement of private incentive and accountability centering on enforcement of property rights and targeted liability for pollution. Environmental Education Project Production and distribution of materials that examine environmental issues based on the latest scientific and economic research. FREE MARKET LEGAL PROGRAM Launched in 1986, this program seeks to carry the battle for economic rights into the legal arena. Issues and cases are selected on the basis of their importance as policy and precedent and on the likelihood that the Institute can make a significant contribution. Some recent activities have addressed FDA reform, rent control, and Corporate Average Fuel Economy standards (CAFE). "Death by Regulation" project Aimed at shifting the policy debate toward market-based approaches to risk management. It attempts to do so not through conventional policy analysis, but by focusing on previously unrecognized victims of regulatory failure. In particular, the project demonstrates that risk management by government can often have lethal effects.

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Remailer REORDER not DELAY
by fnerd＠smds.com 17 Dec '03

17 Dec '03

Jim choate <ravage(a)bga.com> writes: > 2. messages will be cached and re-transmitted after a random delay. I intend > to generate a random number between 0 and 24. When the appropriate hour > arrives all messages with that time stamp will be sent encrypted. > I would suggest getting a random number between 0 and 1440. This will I waited for a good reply to this and didn't see one. Smart people have commented on this before and no one in this round seems to be remembering. Delay--time--isn't what matters. It's confusion about which message is which that matters. So if I get 10 messages in one minute, I can scramble the order and send them out the next minute, and I've done my job--at least the order-scrambling part. (You also need to pad or packetize messages.) So use serial numbers, not times! Send a message for every one you get, keep a fixed number of messages queued, and add dummies if necessary to keep things moving. > On the issue of traffic analysis: > > It occurs to me that simply monitoring a remailers feeds and their traffic > analysis will provide enough information to determine the difference between > bogus (ie random generated) and real traffic... Why not have the dummy message forwarded in a long enough chain and back to you? Then you could swallow it or turn it into another dummy, depending on whether you need to hurry your queue right now. I don't think the amount of dummy traffic is a big problem. You only need enough to keep your queue flowing. Plus, if the remailers only generate dummies when necessary, the total dummy traffic is self-regulating, since multi-hop dummies are x-lax for every remailer they pass through. I like thinking about the traffic pattern with get-one-send-one remailers: A user sends a message, and it seems to bounce from remailer to remailer to remailer...to a final recipient--but no, it was all a shell game! -fnerd - - - - - - - - - - - - - - - the snack that eats like a food -----BEGIN PGP SIGNATURE----- Version: 2.3a aKxB8nktcBAeQHabQP/d7yhWgpGZBIoIqII8cY9nG55HYHgvt3niQCVAgUBLMs3K ui6XaCZmKH68fOWYYySKAzPkXyfYKnOlzsIjp2tPEot1Q5A3/n54PBKrUDN9tHVz 3Ch466q9EKUuDulTU6OLsilzmRvQJn0EJhzd4pht6hSnC1R3seYNhUYhoJViCcCG sRjLQs4iVVM= =9wqs -----END PGP SIGNATURE-----

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