December 2003 - cypherpunks-legacy

Re: java security concerns
by cman＠communities.com 17 Dec '03

17 Dec '03

Simon Spero wrote: >In my previous message, I left out some fundamental parts of the run-time >that need to be looked at carefully. The garbage collection needs to be >examined carefully. Normally GC algorithms are formally derived, so it's >the implementation that needs to be checked for. holes in the GC may be >too unpredictable to exploit for anything but core-dumping, especially since >java uses a mark-sweep conservative collector. > FWIW, we had some ideas about how to attack the GC from untrusted code, involving resurrection of objects during finalization. This turned out not to work -- the Javoids apparently anticipated this problem in their design.

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Netscape & Fortessa
by Michael G. Reed 17 Dec '03

17 Dec '03

All- I remember there was some talk about Netscape adding Fortessa support on here a couple of days ago, so I thought I'd share this. Marc Andreessen (president of technology for Netscape Communications) made a presentation today at the 18th National Information Systems Security Conference about Fortessa support within Netscape 2.0 to be shipping Beta Q2 '96 and final the second half of '96 (I haven't seen an official press release, but he more or less said they were announcing it today). From his description, it looks like they are going to place the Fortessa drivers right in the SSL layer bypassing the software subsystem that currently exists in favor of the hardware (the software subsystem would still be utilized for non-Fortessa sessions). He also commented that this was possibly a lead-in to other hardware subsystems in the future. General reaction (at least in my immediate vicinity in the lecture hall) was quite positive -- looks like Fortessa is gaining even more momentum (Oracle had a talk about Fortessa support immediately after Netscape). I wonder when Microsoft & company will jump on the bandwagon? :-) -Michael (The above statements are my opinions and do not necessarily represent the opinions of the Department of Defense, the US Navy, or the Naval Research Laboratory.)

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Re: java security concerns
by Rich Salz 17 Dec '03

17 Dec '03

>> >By the way, I suggest that Sun should offer a large money prize for >> >the first significant security hole found the Java implementation. Its >> >a tiny price to pay for security. I notice that netscape just announced that they're doing this.

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Re: Java idea
by Bill Stewart 17 Dec '03

17 Dec '03

At 09:54 AM 10/10/95 -0400, Mike Fletcher <fletch(a)ain.bls.com> wrote: > >Well, security bugs aside (and I've got the sun4.1.3_u1 and Win32 ns2b >distributions :) has anyone given any thought to using Java to do some >sort of Chinese Lottery attack. I was re-reading App. Crypto. last >night and it could be feasable. If you could get your key cruncher >thread loaded into a good many browsers to run when idle . . . . How >many estimated copies of NS are there? Anyone want to do the math? :) Yeah, this was discussed; mix it in with a cool screen saver "We're busy hacking Microsoft!" bouncing around the screen and you could probably get a lot of people to try it, assuming of course that it can run in offline mode conveniently, which I'm not sure Netscape can yet (downloading the software, copying mozock/nullsock as winsock, and restarting Netscape doesn't strike me as convenient, which means it's also not an off-line mail/news reader yet.) The negative part is that Java Bytecode interpretation is about 10x slower than native code; you'd have to get people to download native libraries for their platform to do the grunt work. #--- # Thanks; Bill # Bill Stewart, Freelance Information Architect, stewarts(a)ix.netcom.com # Phone +1-510-247-0664 Pager/Voicemail 1-408-787-1281 #---

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Re: Certificate proposal
by Bill Stewart 17 Dec '03

17 Dec '03

At 09:04 AM 10/10/95 -0700, Hal wrote: >Still, there is a problem here: how did the bank know that it _should_ >honor requests to withdraw money from bank account x if they are signed >with a certain key? How did it determine that that is a valid key, if it >never had a secure channel to the person opening the account? I think >the answer is clearly that it cannot, that it must have had a secure >channel. Would a certificated key presented by Alice have been >sufficient to create such a channel, do you think, or would a face to >face meeting have been necessary? (Or would an uncertificated key be >adequate?) I think you're probably right, though a one-way secure channel is enough. If Alice has a trusted copy of the Bank's key, she can open her account and get her key certified by them without them having to trust her key (modulo little details like government requirements that banks get positive identification for their accountholders.) >What if you are accessing the bank via a MITM? Consider this example: >Alice writes you a check, signed with a key (without her name) which >has a credential from the bank saying that it will back up the check. >But you need the bank's key to check the credential, so Alice gives it >to you, or you get it from a public cache. Suppose the bank's key is >fake, and Alice is defrauding you. How do you tell? With online clearing, you'd be able to tell because Alice's check cleared and your bank (which we're assuming you've got a secure channel to) says you've got the money. Or in the case of digicash, because the cash Alice's bank gave you was good. >Wouldn't a certificate on the bank's key be necessary, one which ties the bank's >name and reputation to the key? Maybe not, but it would sure help. >Or what if the bank really is and has always been behind a MITM? You say >that it is more profitable for the bank not to abscond with your money. >What about the MITM? He doesn't make any profits until he cheats. Hmmm. That one's interesting; he pays fakes everything for a while, including paying out money, and then pulls off the Big Con. >It seems to me that a lot of protocols assume the existence of secure >channels. Yet the MITM attack shows that public key cryptography does >not in and of itself provide a secure channel. This is a problem which >IMO should not be ignored simply because it is inconvenient. Agreed. #--- # Thanks; Bill # Bill Stewart, Freelance Information Architect, stewarts(a)ix.netcom.com # Phone +1-510-247-0664 Pager/Voicemail 1-408-787-1281 #---

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Netscape starts their own "Hack Netscape" contest
by Ray Cromwell 17 Dec '03

17 Dec '03

Starting today, Netscape is awarding those who are first to find security bugs in Netscape 2.0 with cash prizes. (see their homepage for more info) -Ray

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Man in the Middle Revisited (but not for the last time)
by tcmay＠got.net 17 Dec '03

17 Dec '03

At 7:03 PM 10/9/95, Hal wrote: >tcmay(a)got.net (Timothy C. May) writes: >>For communication, the only credential Alice needs to ensure that only Bob >>can read her message is that she uses Bob's public key. If "Bob the Key" >>reads it, presumably it was "Bob the Person" who read it. > >>(Again, Bob the Key = Bob the Person to many of us. If Bob the Person has >>let his private key out, so that Chuck the Person is also able to read the >>Bob the Key stuff, etc., then of course cryptography cannot really handle >>this situtation.) > >OK, but again, what about the man in the middle attack? Suppose the >key that you found that claims to be from Bob is actually not his, but >another one created by a man in the middle, such as Bob's malicious >ISP? Then that ISP is decrypting the messages Alice sends to him using >that fake key, and re-encrypting them using Bob's real key. He is >reading all of the messages, and Alice and Bob do not in fact have >communications privacy. There are many, many people on the list that I know only from their posts and their public keys (not that I'm a heavy user of PGP as some of you are, though some of you I have dealt with via PGP messages). I don't know if "Carl Ellison the Key" is "really" the same Carl Ellison that Carl Ellison the Key claims to be...you see the semantic difficulties. What I know is that the Carl Ellison who sends me PGP message and who appears to be working at TIS is not publically disputing messages sent by an MITM attacker. (True, the MITM could be only targetting _me_, and so the "real" Carl Ellison could be unaware that the "fake" MITM Carl Ellison is masquerading as him.) But if I really care I can post a public channel (the CP list, for example) query, encrypted to the known public key (used in many past posts, for example) of "Carl Ellison the Key," asking if he sent the message to me. To put it bluntly, all I really care about is _persistent_ key-holding, i.e., that the person who began posting with a given key is still using the same key. Or, rather, I don't even care if the keyholder "Pr0duct Cypher" is actually a person, or a Bourbaki-style committee--I only care that messages purporting to be from Pr0duct Cypher or Black Unicorn or Carl Ellison are still using the same key. Who any of these entities "really" are is irrelevant to me. (I don't even know if Hal Finney, who I met once a few years ago, is the "real" Hal Finney, nor do I really care.) >I don't want to overstate the risk of this attack. It would not be an >easy one to mount and I believe there are countermeasures which could >detect it unless the MITM had nearly supernatural powers. But the MITM >attack is normally considered seriously in discussing crypto protocols. >It is a well known weakness in Diffie-Hellman, for example. That is why >authenticated Diffie Hellman is used in some of the newly proposed key >exchange protocols for IP. The risks of MITM attacks on public key >systems was recognized not long after those systems were proposed. The >problems with fake keys have been discussed for over a decade. > >Why is this all suddenly irrelevant? Were these attacks never realistic? >Is it just not a problem somehow? I am baffled by the fact that people >are just turning their backs on all these years of research and >experience. If this is some kind of paradigm shift in which the idea of >communicating with keys is seen as the key to the puzzle, then I am >afraid I don't share the enlightenment. To me the problem seems as real >as ever. Well, I'm not saying the work is unimportant. What I'm saying--and I think others are too--is that there is no crisis that calls for "certificate authorities" to provide "proof" that a keyholder is who he says he is. I'm happy continuing to trust that people are who I once they thought they were, by their signatures and their apparent ability to read messages encrypted to their public key. If in fact I am dealing with body-snatchers who actually infiltrated the identity of "Carl Ellison" and are able to act as him, so what? I never met the "real" Carl Ellison, so who cares if Carl Ellison the Key is really Carl Ellison the Biological Entity who Grew up in Foobar, Pennsylvania and Graduated from Bobby Ray Inman H.S. in 1975? That's all. If people want to work on credentials and similar certificate processes, that's great. But I'm saying I see no compelling need _for myself_ and will strongly argue against some of the reasoning we are hearing about why certificates need to be issued. (Because I have also read the Postal Service proposals that they get into the business of certification of e-mail in various ways, and because of the various other schemes being discussed which seem less than voluntary.) --Tim May Views here are not the views of my Internet Service Provider or Government. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay(a)got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^756839 | black markets, collapse of governments. "National borders are just speed bumps on the information superhighway."

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Java idea
by Mike Fletcher 17 Dec '03

17 Dec '03

Well, security bugs aside (and I've got the sun4.1.3_u1 and Win32 ns2b distributions :) has anyone given any thought to using Java to do some sort of Chinese Lottery attack. I was re-reading App. Crypto. last night and it could be feasable. If you could get your key cruncher thread loaded into a good many browsers to run when idle . . . . How many estimated copies of NS are there? Anyone want to do the math? :) --- Fletch __`'/| fletch(a)ain.bls.com "Lisa, in this house we obey the \ o.O' ______ 404 713-0414(w) Laws of Thermodynamics!" H. Simpson =(___)= -| Ack. | 404 315-7264(h) PGP Print: 8D8736A8FC59B2E6 8E675B341E378E43 U ------

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How to hold a key signing party?
by jpb＠miamisci.org 17 Dec '03

17 Dec '03

-----BEGIN PGP SIGNED MESSAGE----- I've never attended a key signing party so I'd like to get some input on the most effective way to run one. What I have in mind is to have everyone who is planning on attending send me their key and its fingerprint. I'll collate the lot and print enough copies of the list of names/fingerprints so that once everyone shows up, each person can get a handout. Everyone presents ID showing who they are and reads off their fingerprint so the attendees can check them on their handout. Afterwards, I'll email all attendees the keys so they can sign them and mail them back to me. Once I receive the signed keys, I'll redistribute them back to the owners & attendees. This seems like a lot of work, which I don't mind, but if there is a more efficient method, I'd like to know about it. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQEVAwUBMHrs/mGnwFiC3O2NAQGmMgf/SMeupR1BLe63riBNQklOGgGrLm+7yW3d cqR42cdHnfxGLjy9Jwp+kmN1mHMf+EA+VIEZGC98Q0ZzwGzAnlibXmBOCHuC+6u2 ofRGLXtOB8WKJlJ2uXNjAeeOQcCEaRXmgbPhtqgb2YH7zcsiFRWMjpTi3MwLylXv Vb7SIgayVKuGEx2h43xH0ChjJuyzsdJgRtW5G0e/oBjxcOpdtNrnj4zHmFqu9R/M o4NN/W1S2unF3nvJmZkpKQT7EdVbRFHjdS/RfSqTcqf+WF+yXCo2NnUkdUat5uJh QB1CpIn7Zpw/HZiAp5r87GFy0SiKvwS4QPpsvhIaCa0NGoNqqjhXUg== =Jvxf -----END PGP SIGNATURE----- signoff 2048bit-Fingerprint: 74 64 C7 6F 51 72 36 3D 87 75 F9 F5 2A F6 8F 74 ------------------------------------------------------------------------ Help Phil! email zldf(a)clark.net or see http://www.netresponse.com/zldf

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Re: Certificate proposal
by tcmay＠got.net 17 Dec '03

17 Dec '03

At 4:46 PM 10/9/95, Hal wrote: >Bill Stewart <stewarts(a)ix.netcom.com> writes: .... >>also a signed attribute statement from the Bank's key that it's a bank, etc. >>The meaning of the certificates changes a bit, but there's still a certificate >>from the bank binding Alice's Key to Alice's Bank Account. > >I can see using keys with attributes in this way, for credentials or as >other forms of authorization. But what about for communications privacy? >What is the attribute that tells you that using this key will prevent >eavesdropping? For communication, the only credential Alice needs to ensure that only Bob can read her message is that she uses Bob's public key. If "Bob the Key" reads it, presumably it was "Bob the Person" who read it. (Again, Bob the Key = Bob the Person to many of us. If Bob the Person has let his private key out, so that Chuck the Person is also able to read the Bob the Key stuff, etc., then of course cryptography cannot really handle this situtation.) --Tim May Views here are not the views of my Internet Service Provider or Government. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay(a)got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^756839 | black markets, collapse of governments. "National borders are just speed bumps on the information superhighway."

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