December 2003 - cypherpunks-legacy

Re: ID of anonymous posters via word analysis?
by felix＠hu.se 17 Dec '03

17 Dec '03

>Edward J OConnell writes: >One could also imagine a 'symantic scrambler' analogous to the word >analysis program, but designed to defeat it, by randomly altering the >syntax of a post. It doesn't have to be random. You could have a neural network style translation of sentences. You would train the network by having a known pre-written sentence as output, and a sentence with the same meaning, but with your personal syntactic style. It would also be possible to do lexical or paragraphical translation. With this scheme, you can have as many writing styles as you want (e.g. one for each poster). If you want to look like Shakespeare, just train the network with a couple of (pair of) sentences of Hamlet. ---------------------------------------------------------------------- True Name: Felix Ungman "Gen is god and your God is not"

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ANON: anonymous mail
by nobody＠indirect.com 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I thought I'd describe why you would want to pad anonymous mail. Currently, the destination and contents of email you send isn't private. It is possible for any number of people to snoop your mail as it travels to its destination. For privacy, you can encrypt your mail. Suppose Alice has an email account as learns that email is about as private as a postcard. She decides to encrypt all of her email, and all of her correspondents agree to do the same. So now, nobody can read her mail. But, who she communicates with still yeilds information. This is called traffic analysis, and I won't go into it here. So, enter anonymous remailers (see Chaum's "Untraceable Electronic Mail"). Currently several people on this list are experimenting with and running anonymous remailers. The remailers accept instructions (optionally encrypted) and resend messages, making it look as though the mail originates from the remailer. Now Alice sends and receives all her encrypted mail from an anonymous remailer. Somebody snooping Alice won't learn the contents of her mail, or even with whom she communicates. (She could even keep private what USENET news she reads by borrowing a trick from Mr. Slippery in "True Names" - just download everything and read what you want at home.) Another security enhancement is chaining the anonymous remailers, instructing one to mail to another, and so on, eventually delivering mail. Alice and her friends do the same, and they continue to privately communicate, keeping their various identities secret. If the snooper just watches the first remailer, he will learn that her mail goes to another remailer, etc. Now the snooper would need to watch more remailers to figure out who Alice is talking to. - From time to time, people suggest a probabalistic remailer, either forwarding mail to another remailer, or delivering it immediately. This actually reveals the final destination to more remailers than before. For example, if Alice chains mail A-B-C-final, then only the C remailer knows the final destination. But if the remailers implemented some probabalistic scheme, then each one will have to be given the final destination. To make it harder for a snooper, the remailers decide to cache their remailing requests, sending them out periodically instead of immediately. Now, a snooper would see a steady stream of mail into the remailer, and nothing coming out until suddenly, the remailer sends out all of its queued messages. If a large number of messages are stored to be remailed later, the snooper isn't able to easily match up incoming and outgoing messages. Now we come to message padding. If a snooper watches the incoming and outgoing mail, perhaps the size of the mail will provide enough information to link sender to destination, even if it is cached and remailed along with several other messages. So, to defeat this, the remailer can pad all messages to be a certain length. The best way for this to work is if a snooper can't figure out what is padding and what isn't. For plaintext and digitally signed (only) documents, this is not too difficult. But, for encrypted messages, if the remailer could insert padding into the encrypted text itself, or add in padding which would be ignored upon decryption, then it would be very difficult, if not impossible, for a snooper to determine what is and what isn't padding. The system implemented at the elee9sf(a)menudo.uh.edu remailer is a simple type - it pads the message body to a certain length. But it is pretty obvious what is padding and what isn't - so if a snooper is in a position to determine the length of a message (say they are trying to match up source and destination), they probably will be able to read the message and throw the padding out on their own. A better system would be one that pads inside encrypted text. This can be done with a pgp encrypted message by padding the end of ascii encrypted text and adjusting a few bytes (length fields, etc.). The message can still be decrypted, and the excess padding bytes will be ignored. Such a system is in the works... and it is reasonable to pad encrypted messages since it is much harder to detect and you will probably encrypt text sent through an anonymous remailer to get the maximum benefit. (If you don't mind everyone reading what you wrote you could use a dc-net and generate plaintext :-) Another useful technique is an anonymous pool, where everybody in the pool gets every message. Since everybody subscribing to the list receives every message, it would be extremely difficult for a snooper to determine to whom such a message is really intended for. You could use a newsgroup for the same purpose - post encrypted text to some group and your friend would read the group and retreive the message. Also, from time to time people wonder about errors and whether failed mail can be bounced back or whatever. The difficulty here is that the anonymous remailers try to keep information about source and destination to a minimum. For instance, a message may be routed through several remailers; the previous hop may be another remailer, so it wouldn't be useful to bounce the message back. Some remailers drop bounced mail, others wind up appending to a log file. A good solution currently implemented at extropia.wimsey.com is to use an anonymous pool for error reporting. Karl Barrus <klbarrus(a)owlnet.rice.edu> -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLNH9eYOA7OpLWtYzAQEPzQP/QYeciQf7TKimj67xQRWScov848bcauF6 hlFOfoF4MFSm7mhD1bPks7xiwZuYO6P+MwkaeMqBKYQfWzBi37Blx5PNo3iK6Dmk pmeGsYqew34oPxk7Exvsu7uOcKhFAhBcEWvElJ+ytMjEbuY8EsHoGGETXpPVK87C OFkNxCrdqYY= =J/5q -----END PGP SIGNATURE-----

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Re: Paranoid
by Karl Lui Barrus 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I'm not exactly sure what this thread is about :-) but I do have some numbers: Differential cryptanalysis of DES requires 2^47 = 140737488355328 = 1.4 10^14 known plaintexts. The complexity of a brute force DES attack (keysearch) is 2^56 = 72057594037927936 = 7.2 10^16, or 2^55 = 36028797018963968 = 3.6 10^16 if you are efficient. Similary, brute forcing IDEA is 2^128 = 340282366920938463463374607431768211456 = 3.4 10^38 The best factoring algorithm (gopher plug: check in Misc/ for a recent "bits and difficulty factoring post") for a 1024 bit key is a complexity of 4.42 10^29. Somewhere around 1600 bits comes a point where it is "easier" to attack IDEA than factor the resulting number. Karl Barrus <klbarrus(a)owlnet.rice.edu> -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLNKNqYOA7OpLWtYzAQFlkwP+PdenJNJOKm9zcxkL4Zaq22aujfa2SAgk 1NILjQzZI8uZe9FIn8p2uEoS3YjYskg40tEMeohhGqZ371s/ndlTjDDhga0PCXLj Q4UHoowTVR9hx/cVGzLhuZbyAwbbqAvygGQNKN1iXn3IqpLoNV3Do+TtUj0xLt1l 0j1gl055YL4= =Vl2r -----END PGP SIGNATURE-----

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thanks...
by jdblair＠nextsrv.cas.muohio.EDU 17 Dec '03

17 Dec '03

Thanks to all of the people who answered my question on message signing. -john.

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Macintosh PGP CDEV Idea
by jdblair＠nextsrv.cas.muohio.EDU 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I have a proposal for a piece of code I'd like to try and put togethor over Xmas break, and I want to bounce it off of the group to make sure that I'm not duplicating anyone else's work. I work mostly on the Macintosh, and this program would be for the mac. It would be a CDEV (good 'ol desk accessory) which would contain a smaller version of PGP. By smaller, I don't mean less secure, I mean a little less functionality. All it would do would sign, encrypt, or decrypt text files. By being a desk accessory, it would allow a message that's been downloaded by whatever means (MS Mail, FTP, Kermit, etc.) to be quickly decrypted, or to encrypt files for uploading. The idea is to have a simple, easy graphical interface on a small floating pallete type window. Since it would be a CDEV, it could be used simultaneously with a communications program even if the machine was running 6.0 w/ the unary finder. Keys would still be generated in the full fledged version, but these keys would be accessible by the CDEV. A possible later version could also take advantage of Apple Events, thus becoming a module which other programs could send files to to become decrypted, or encrypted without worrying about the process themselves. I've begun poreing through the source code to see how easy or difficult this is going to be, but first I'd like to make sure that their aren't already projects like this in development, or if there is any body who would like to help with the development process. It must be made clear that I am a beginning C programmer and a beginning developer of hard-coded Macintosh applications. I've started to consider tackling this project as something that will force me to learn both. Anybody have any ideas, comments, proposals? E-mail me directly, unless you think its a discussion that should be posted to the group as a whole. later, - -john. -----BEGIN PGP SIGNATURE----- Version: 2.3 iQBVAgUBLNJm3qNqtARNqVmxAQGL2wH/dYM7nkpeNbrFniRseZUHEl0X1p4Cn5md iqPkZWhznhwa+QhcEm6s8RGSq/Kf/uEPsy1C58wVfFbwhMF23WfPhQ== =car+ -----END PGP SIGNATURE-----

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Has anyone seen "Applied Cryptography" yet ?
by trestrab＠GVSU.EDU 17 Dec '03

17 Dec '03

If anyone has seen Bruce Schneir's new book, "Applied Cryptography", please post a short review to the list so that others can know whether to special order it. Thanks. Jeff

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Re: Digital cash announced today by UK bank.
by cypher01＠eternity.demon.co.uk 17 Dec '03

17 Dec '03

In message <199312091906.TAA22687(a)an-teallach.com> gtoal(a)an-teallach.com writes: > Apparently the Natwest Bank (or some spoonerism thereof) announced > today that they were releasing digital cash in the form of some > sort of smartcard. I have no more details - does anyone else? > I saw this a few days ago in the Guardian. Big front page splash, and lots of radio coverage. The system is called "Mondex". I'm looking into it, myself, as I know about as much as you do. Midlands Bank is cooperating in the scheme, which is not surprising, as they already have shared-ATM agreements. > Primarily I'm interested in knowing if it's *anonymous* digital > cash - knowing our govt, I suspect it's unlikely to be. Any new > opportunities to track the masses are always gratefully received > by the powers that be... > Interestingly, none of the press coverage even mentioned the *issue* of privacy. I've told Tom Burroughes at the East Anglian Daily Times (tom(a)reptile.demon.co.uk) he's deputy chief reporter there, and was a speaker at ECFP '93. He's looking into it now; if you wish to speak to him, call 0473-230-023 and ask for him in the newsroom. He may be out, as he's also chief court and legal reporter, but he always calls back. I'll be calling Australia in a few minutes to see if I can raise Simon Davies, who's out there on business. Simon (davies(a)privint.demon.co.uk) is director of Privacy International, and was another ECFP speaker... the most well-connected privacy advocate I've ever met. > G > > -- Russell Earl Whitaker whitaker(a)eternity.demon.co.uk Communications Editor AMiX: RWhitaker EXTROPY: The Journal of Transhumanist Thought Board member, Extropy Institute (ExI) Co-organizer, 2nd European Conference on Computers, Freedom and Privacy, London, October 1994

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USENET on a tape, and future privacy
by nate＠VIS.ColoState.EDU 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I was just thinking. My roommate mentioned that he saw an ad for a service available in europe. They send you an 8mm tape evey week that has all the USENET traffic on it. I was thinking that a large corporation thinking of hiring me (or you, you just never know!) could pay some service to scrounge up all the USENET posting you have made for the last, say, 10 years, and run them through a filter to get a feel for the nature of the posts (assuming you were too prolific to have the job-hunters read _al_ of your posts). This really scared me, so I think I will start making more frequent use of the remailers in the future. Just my $0.02 (revalued to $15.00 with recent inflation) - -nate - -- +-----------------------------------------------------------------------+ | Nate Sammons nate(a)VIS.ColoState.Edu (303) 491-1578 | | Colorado State University -- Computer Visualization Laboratory | +-----------------------------------------------------------------------+

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Please unsubscribe from mailing list
by Paul Rushizky 17 Dec '03

17 Dec '03

Please unsubscribe me from your mailing list. Thanks.

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Re: "Cipher"
by grand-central!amix!chip 17 Dec '03

17 Dec '03

Arthur Chandler writes: > Neil Postman, in his *Technopoly*, asserts that the word "cipher" derives >ultimately from the Hindu word for void, and therefore "suggests the idea >of nothingness." (p 128) Does anyone else have info on the origin of this >word? Is Postman correct? Postman may be right about his etymology; I don't know, though I'm sure one of the many folks out there with an OED could answer this. However, arguing from etymology is one of the most irksome of the many bogus rhetorical techniques that the academic establishment has developed as part of its standard toolkit and really wish they would cut it out. The answer to the broader question, "Is Postman correct?", is "no".

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