- cypherpunks-legacy - lists.cpunks.org

Mea Culpa - Don't "devalue" my postings :-(
by msattler＠netcom.com 17 Dec '03

17 Dec '03

>> The real question is, what attorney jokes do *you* know? Do you tell >> programmer jokes? > > Why did you post this to the list? Argh! I'm using a new mailer that copies *everyone* to the reply field, which I've noticed only after investigating (prompted by someone's gentle query). I'm sending this apology to the list because I'm sensitive to preserving a high signal-to-noise ration, and I understand that my exchange of attorney and programmer's jokes with Mike @ EFF should be private mail. I'll me more mindful in the future. Sorry. Now let me try and make this message add something. I love the idea of implementing a digicash system monitored by the list server even though we haven't finished discussing whether it's play money, or how to charge exactly. Getting it up and running and generating usage statistics so we can see the flow of digicash. Again, I aplogize for having my private email replies leak onto the list. ----------------------------------------------------------------------------- Michael S. Sattler msattler(a)netcom.com +1 (415) 358-3058 Digital Jungle Software Encrypt now; ask me how. (finger for PGP key) Evil will certainly triumph if good people do nothing at all.

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Help people help themselves
by Huba J. Leidenfrost 17 Dec '03

17 Dec '03

Yikes! So how does one unsubscribe to this list? Not that I want to unsubscribe, but from the number of people that post their subscribe and unsubscribe messages directly to the listserver, I take it this is a problem? Or are they simply illiterate? Could somone please email me or post the proper method to unsubscribe and resubscribe? Thanks. -- --- O | HUBA LEIDENFROST -- <^- | leide871(a)snake.cs.uidaho.edu -- -\/\ | `No it's not an original--I stole it off the net!' --- \ | ADVICE AVAILABLE

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Re: MacPGP 2.3 sources
by an5877＠anon.penet.fi 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- > Connected with the fault, if anyone knows of the domain name or whereabouts > of the machine with IP number 179.135.226.153, I would be most interested > in contacting its manager. You have been hacked. IP addresses above 168.xxx.xxx.xxx have not yet been allocated. DEADBEAT <na5877(a)anon.penet.fi> -----BEGIN PGP SIGNATURE----- Version: 2.3 iQBFAgUBLLQZrPFZTpBW/B35AQEcPgGArD2mpFu4Sd7oj+s95XRgJtfW9lo/I/Ln y14lstlkI1wS0XsHDPZnC/6FOZrokyOK =57Jo -----END PGP SIGNATURE----- ------------------------------------------------------------------------- To find out more about the anon service, send mail to help(a)anon.penet.fi. Due to the double-blind, any mail replies to this message will be anonymized, and an anonymous id will be allocated automatically. You have been warned. Please report any problems, inappropriate use etc. to admin(a)anon.penet.fi.

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Weak RSA keys?
by Karl Lui Barrus 17 Dec '03

17 Dec '03

I don't mean to flame you, but before you rush off and publish your results somewhere you may want to step back and check over your premise and the steps it involves a few times. > The "spare" is 7. The "spare" runs faster, too. Go ahead, try it. > The myth is that "ED = 1 mod (m)". > The truth is as follows: > G = gcd( p-1 , q-1) in this example G=2 > F = m/G in this example F=20 > ED = 1 mod (F) Now how exactly do you calculate this "F"? Does it involve, say, knowing phi(n), information ONLY available to you if you happen to know the factorization of n? In which case the whole thing collapses anyway? How can you use this information to decrypt a message? If I were to give you the 200 digit product of two primes, could you find the "spare" key? If I get some time I'd like to look over your method to see if it's really there or an artifact of the numbers you chose. There is a "weakness" easily shown in RSA in that for some keys, up to 9 messages encrypt to themselves! That is, M^e = M mod n. Now, if you pick large primes, these 9 messages will get lost in the 100 trillion numbers every atom in the universe can have allocated, so it really isn't a problem. -- Karl L. Barrus: klbarrus(a)owlnet.rice.edu keyID: 5AD633 hash: D1 59 9D 48 72 E9 19 D5 3D F3 93 7E 81 B5 CC 32 "One man's mnemonic is another man's cryptography" - my compilers prof discussing file naming in public directories

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Good editorial in the Merc
by doug＠netcom.com 17 Dec '03

17 Dec '03

The Thursday Oct 7 San Jose Mercury News lead editorial contains a note acknowledging a sane point of view about cryptographic exports. (It's titled "Unshackled Tech -- Looser export rules will boost Silicon Valley Sales", and it discusses Clinton's decision last week to boost the speed limit for exportable computers.) The *good* part, though, is: " * Congress should update the Export Administration Act. A 1990 version would have lifted export controls on telecommunications and software with encryption codes, which give the software users a better way to keep data secret. President Bush vetoed it. His administration wanted to deprive the Chinese and Russians of the latest, hard-to-bug telecommunications equipment, and the latest encrypted software. Well, the Chinese already know how to make the new telecommunications equipment. The encryption software is in the hands of anyone who can find a pirated copy." Awareness is beginning to grow out there. Doug

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Re: Standard Headers for Anonymous Remailers
by peb＠PROCASE.COM 17 Dec '03

17 Dec '03

>From: pierre(a)shell.portal.com >Who qualifies whom, based on what info, and to eliminate whom? As the Internet becomes more diverse and less the domain of programmers and scientists, it is natural that other means of selection are needed for membership in a group. The traditional academic atmosphere of mailing lists will evolve away from total openenss. Here are some possibilities: 1. By invitation only--members sponsor new members. 2. By trial period--new members are lurkers on the main list and a subset of the members can see their postings or they must first be moderated. 3. Qualifications--could range widely. 4. Tests. 5. All of the above. >From: owen(a)autodesk.com >with authentication qualifications for *entry* or transaction The Extropians list already does this--not totally secure, to be sure, but you must let the list administrators know all your posting nodes. Paul E. Baclace peb(a)procase.com

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Weak Keys? explained
by charliemerritt＠BIX.com 17 Dec '03

17 Dec '03

No, I did not mean I can find the spares of a well constructed key. And yes, the best key has at least one spare. What I meant was, if I were the NSA and wrote the keygen for a crypto system I could guarantee that each key would have a huge number of spares. Enough, that if I were the NSA I could find them. How to generate a weak RSA key: Start with a prime R S=R*2 L1 If S+1 is prime then P=S+1 If S+1 Not prime S=S* next_odd_number (3,5,7,9,11...) Loop to L1 else L2 If S+1 is prime then Q=S+1 If S+1 Not prime S=S* next_odd_number Loop to L2 else N=P*Q #spare keys => 2*R In the example I gave R was 101 p=1+(101*2*3) q=1+(101*2*2*3) spare keys=606 There are many BETTER ways to make a keygen that will produce keys the author can break. RSA has no government trap door, but I, and certainly the NSA can write a keygen that makes trap-doored keys. Ones YOU can't break, but I can, knowing my secret. My example was a put-down of Denning's assurance that skipjack is good. RSA is good, skipjack MAY be good. Look out for booby trapped keys.

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Internet Security Scanner, description
by remail＠tamsun.tamu.edu 17 Dec '03

17 Dec '03

Just in case you think your machine on the Internet is secure enough for remailers, storing private files, etc. here's the author's description from the source code shell archive as posted to comp.sources.misc. It would be a big confidence booster if remailer sites demonstrate that they have passed ISS and other Internet security tests. ---------------------- Internet Security Scanner (ISS) is one of the first multi-level security scanners available to the public. It was designed to be flexible and easily portable to many unix platforms and do its job in a reasonable amount of time. It provides information to the administrator that will fix obvious security misconfigurations. ISS does a multi-level scan of security, not just searching for one weakness in the system. To provide this to the public or at least to the security conscious crowd may cause people to think that it is too dangerous for the public, but many of the (cr/h)ackers are already aware of these security holes and know how to exploit them. These security holes are not deep in some OS routines, but standard misconfigurations that many domains on Internet tend to show. Many of these holes are warned about in CERT and CIAC advisories. This is the first release of ISS and there is still much room for improvement. ISS is a project that I started as I became interested in security. As I heard about (cr/h)ackers breaking into NASA and universities around the world, I wanted to find out the deep secrets of security and how these people were able to gain access to expensive machines that I would think were secure. I searched Internet for relative information, such as Phrack and CERT advisories. Most information was vague and did not explain how intruders were able to gain access to most systems. At most the information told administrators to make password security tighter and to apply the vendor's security patches. They lacked real information on how an intruder would look at a site to try to gain access. Having talked with security experts and reading CERT advisories, I started trying to look for various security holes within my domain. To my surprise, I noticed that many of machines were adequately secured, but within a domain there remained enough machines with obvious holes that anyone wanted into any machine could attack the weak 'trusted' machine and from there could gain access to the rest of the domain. From this project, I have not learned any new deep secret to cracking systems, but with the right tools that most domains on Internet are insecure. These holes will not be a surprise to any advanced intruder, but with this tool administrators will be able to quickly search for obvious holes and prepare to fix them.

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Re: that internet security scanner
by smb＠research.att.com 17 Dec '03

17 Dec '03

anyone actually seen that thing? (to refresh: CERT posted some warning about a security scanner for Internet systems that might be the evil work of themthere hackers so you just better delete it, etc etc.) CERT isn't that stupid. What they said was that ISS has been posted, and that it was likely that some folks would try to use it to break into various systems. Do you disagree with that statement? They also said that you should consider running it yourself, so that you can close the holes first. They even gave the pointer to the directory on UUNET where it's stored. What good would it possibly do to delete it on your own machine, when many thousands of other machines around the world have copies? Again -- CERT isn't stupid. --Steve Bellovin

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second order homophonic substitution
by peter honeyman 17 Dec '03

17 Dec '03

a faq on this list (and other places) is whether it is possible to encipher a message in such a way that the resulting ciphertext can be deciphered into a different (harmless?) message. i mentioned on sci.crypt that a second-order homphonic substitution does just this, but it seems to have been missed by the cpunx readership. so, just to prove that i can read denning and still type, here is a brief explanation. (not brief enuf, sorry.) a homophonic substitution maps letters from the plaintext alphabet into sets of letters from the ciphertext alphabet. to encipher, you pick an arbitrary letter from the image of each plaintext letter. usually the intent is to disguise single letter frequency statistics. it's still not very strong, since it doesn't disguise digram or trigram statistics. (also, it seems to me that it would be vulnerable to the same sort of attack used on running key ciphers.) need an example? see denning, p. 70. to build a second order homophonic substitution cipher, you construct an n by n table, where n is the size of the plaintext alphabet. (say n = 26). initialize each entry in the table by a unique element from the ciphertext alphabet. (say, the integers from 0 to 26 * 26, permuted arbitrarily.) this table constitutes the key. to encipher a message, select a "dummy" message (say the itar regs). to encipher the i-th plaintext letter, say p sub i, grab the i-th dummy letter, say d sub i, and output table[d sub i, p sub i]. to decipher, find the ciphertext letter (or number, in this case) in the table at row i and column j. to recover the actual message, output the j-th plaintext alphabet letter. to recover the dummy message, output the i-th plaintext alphabet letter. i.e., the rows give the dummy message, while the columns give the actual message. simple stuff. here's an example. table: D E G I N O S T U D 01 02 03 04 05 06 07 08 09 E 10 11 12 13 14 15 16 17 18 G 19 20 21 22 23 24 25 26 27 I 28 29 30 31 32 33 34 35 36 N 37 38 39 40 41 42 43 44 45 O 46 47 48 49 50 51 52 53 54 S 55 56 57 58 58 60 61 62 63 T 64 65 66 67 68 69 70 71 72 U 73 74 75 76 77 78 79 80 81 here is some ciphertext: 64 11 05 32 49 77 57. it's clear how to extend this to n-th order. peter

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