The last eight messages I see on cypherpunks (sorted by date, threaded) are forwards of messages from Perry's crypto list. Perry's list is archived publicly on the web if anyone subscribing to cypherpunks but not his list is interested in the discussion -- so let me humbly suggest that might be possible not to forward each message. One is enough. Less is more. Let's eliminate redundancy, thus eliminating redundancy. -Declan "TCM" McCullagh On Tue, Aug 17, 2004 at 03:09:58PM -0400, R. A. Hettinga wrote:
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Delivered-To: cryptography@metzdowd.com Date: Tue, 17 Aug 2004 11:10:58 -0400 From: Thomas Harold <tgh@tgharold.com> User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040616 To: cryptography@metzdowd.com Subject: Re: MD5 collisions? Sender: owner-cryptography@metzdowd.com
Eric Rescorla wrote:
Check out this ePrint paper, which claims to have collisions in MD5, MD4, HAVAL, and full RIPEMD.
http://eprint.iacr.org/2004/199.pdf
The authors claim that the MD5 attack took an hour for the first collision and 15 seconds to 5 minutes for subsequent attacks with the same first 512 bits.
I'll play the newbie and ask the question... how would this be used in a practical attack against MD5 (or the other hashing algorithms)?
From my limited understanding, MD5 is usually used as a hash to detect tampering in a particular bitstream. In which case, the attacker's goal would be to calculate how to change bits in the bitstream without changing the MD5 output. (And hopefully without making the bitstream a different size.) Is this where collisions come into play?
Alternatively, hash functions can be used to store passwords (salt + plain text password => hash function => password file). But I don't see where the attacker could use collisions for that.
[Moderator's note:
You might want to read up on hash functions and their uses -- "detecting tampering" in the sense you mean isn't the main use of hash functions these days though they are certainly employed in such applications. Hash functions are a primitive used in all sorts of places as part of MACs, as ways of enabling signature systems, as elements of commitment protocols etc. The use in commitment protocols is totally blown by the current results, btw.
For purposes of things like x.509 certificates, as message integrity codes, etc., the current attacks don't provide an immediate way to attack the system, but they make one worried about the health of the algorithms -- probably sufficiently much to motivate quickly abandoning them for ones that are not vulnerable to these attacks.
--Perry] --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@metzdowd.com
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-- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
At 7:33 PM -0500 8/17/04, Declan McCullagh wrote:
One is enough. Less is more. Let's eliminate redundancy, thus eliminating redundancy.
-- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
At 09:04 PM 8/17/04 -0400, R. A. Hettinga wrote:
At 7:33 PM -0500 8/17/04, Declan McCullagh wrote:
One is enough. Less is more. Let's eliminate redundancy, thus eliminating redundancy.
LMAO RAH :-) ================================================= 36 Laurelwood Dr Irvine CA 92620-1299 VOX: (714) 544-9727 (home) mnemonic: P1G JIG WRAP VOX: (949) 462-6726 (work -don't leave msgs, I can't pick them up) mnemonic: WIZ GOB MRAM ICBM: -117.7621, 33.7275 HTTP: http://68.5.216.23:81 (back up, but not 99.999% reliable) PGP PUBLIC KEY: by arrangement Send plain ASCII text not HTML lest ye be misquoted ------ "Don't 'sir' me, young man, you have no idea who you're dealing with" Tommy Lee Jones, MIB ---- No, you're not 'tripping', that is an emu ---Hank R. Hill
At 7:33 PM -0500 8/17/04, Declan McCullagh wrote:
One is enough. Less is more. Let's eliminate redundancy, thus eliminating redundancy.
Yawn. "Let's" piss up a rope, shall we? Cheers, RAH -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
Oh, so it was RAH who was responsible for the repeated random useless forwards? I hadn't noticed. How uncharacteristic of him. Never would have guessed. -Declan On Tue, Aug 17, 2004 at 09:06:20PM -0400, R. A. Hettinga wrote:
At 7:33 PM -0500 8/17/04, Declan McCullagh wrote:
One is enough. Less is more. Let's eliminate redundancy, thus eliminating redundancy.
Yawn.
"Let's" piss up a rope, shall we?
Cheers, RAH
-- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
At 8:58 PM -0500 8/17/04, Declan McCullagh wrote:
I hadn't noticed. How uncharacteristic of him. Never would have guessed.
...and my mother dresses me funny? You can do better than that, Declan -- if you do say so yourself. Self-important git. -RAH -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
Sigh. RAH has descended to the level of a net.kook. Never would have guessed. -Declan
On Tue, 17 Aug 2004, Declan McCullagh wrote:
Sigh. RAH has descended to the level of a net.kook.
Never would have guessed.
-Declan
Since when is on-topic crossposting an issue here? -- Yours, J.A. Terranson sysadmin@mfn.org 0xBD4A95BF "...justice is a duty towards those whom you love and those whom you do not. And people's rights will not be harmed if the opponent speaks out about them." Osama Bin Laden - - - "There aught to be limits to freedom!" George Bush - - - Which one scares you more?
At 01:02 AM 8/18/2004, J.A. Terranson wrote:
Since when is on-topic crossposting an issue here?
Since forever. Since before either of us joined the list (and I first started reading a decade ago). It's a matter of politeness and degree. A pointer to a discussion archived on the web is more useful than dozens of forwarded messages. Hey, I have an idea! Why don't I write a script crossposting everything from sci.crypt to cypherpunks! How about a few dozen other "on-topic" newsgroups and mailing lists too? -Declan
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 At 1:40 AM -0400 8/18/04, Declan McCullagh trots out the Cypherpunk Purity Test, among other tasty bits of speciousness:
At 01:02 AM 8/18/2004, J.A. Terranson wrote:
Since when is on-topic crossposting an issue here?
Since forever.
To elucidate this a bit, Declan believes in this obscure WELL.nonsense called "you own your own words". No. Seriously. *Nobody* can forward *anything* you say, *anywhere* on the net, without your permission. On the net. Without your permission. Pardon me. Almost 10 years after I heard of it, my stomach still hurts from laughing at this ignorant blend of "communitarian" hippy-logic and 19th century industrial-age legal nostrum. Hint, Declan: the definition of property, especially digital property in an age of perfect digital copies on a ubiquitous geodesic :-) internetwork, is that it's sitting, preferably encrypted, on my hard drive. The, um, bald, fact is, once it's there, I can send it, anywhere on the net, whenever I feel like it, without your "permission". Declan's actual subtext in this case is that he's written this nice summary article on ... wait... where do you work this week, Declan? Time Magazine? No. Not there anymore. Wired, right? No, not there either. Oh, that's it, CNET. Still there, right? CNET probably can't hire enough fact-checkers, so you're probably safe there for a while until the cacophony of protests from your misquoted article subjects rises above a dull roar. Reminds me of a cartoon in Tom Wolfe's "Mauve Gloves and Madmen, Currier and Vine" about the Guy Who Peaked Too Soon. Anyway, as usual, Declan has, dutifully, one imagines, ground out something he wants you to read instead of seeing (mostly relevant :-)) first sources in more or less real-time, on this list where you read it, instead of interrupting your flow to click around on the web for it. This way, though, he "owns" the words, you see. And, obviously, if you click the link, provided here as a courtesy, <http://zdnet.com.com/2102-1105_2-5313655.html?tag=printthis>, he gets paid more money. Sooner or later. Or at least they might pay his way to more conferences, like they used to during the Clinton Internet Bubble :-). Maybe. Anyway, maybe if we all click it a lot of times, Dear Declan might sit down, shut up, and move that sock from his trousers to his pie-hole. By the way, the reason I didn't send *that* article to the list, too - -- before he pissed on my shoes -- is that he whines at you offline about it. And, before this, I took pity on the once-richer-now-poorer erst-ink-stained wretch. Fuck that. I expect to be getting a phone call from CNET's lawyers for copyright violations under COPA, or whatever, now, as a result, but what the hell.
Since before either of us joined the list (and I first started reading a decade ago).
Here we go, folks. The ol' cypherpunks purity trick. "My tenure on these lists longer than yours." Or, "I've been voting libertarian longer than you have." Or, "I play on Cato's Invisible Foot and you don't." Or, "I can dry-jack a Mossberg, or Nikon Coolpix, or whatever, faster than you can." Or whatever. For the record, I've been here since March or April of 1994. Whatever. This list, and it's lineal predecessors, is long past the time when cutting edge cryptography was discussed here for the first time instead of somewhere else. So, periodically, the tree of cypherpunks must be watered with the blood of other lists. Or something. :-) In the meantime, remember that Declan's main purpose here is to sniff around for stories. Which is fine, until he starts pretending he's Tim May (I knew Tim May -- he wished I didn't -- and, Mr. McCullagh you're... Oh, forget it), or, paradoxically for cypherpunks, that he owns the list somehow, and that, like Mighty Mouse, he's here to save the day and play list.policeman.
It's a matter of politeness and degree.
True enough. And, frankly, I've respected both of those in what I've sent here over the years. The only people who've complained, at least until I've explained myself to their satisfaction, have been "professionals" who "owned their own words" and got scooped. If one can consider forwarding something important from cryptography to this list to be "scooping" the CNET Political Editor in Chief. Or whatever they say he is these days.
A pointer to a discussion archived on the web is more useful than dozens of forwarded messages.
Hey, I have an idea! Why don't I write a script crossposting everything from sci.crypt to cypherpunks! How about a few dozen other "on-topic" newsgroups and mailing lists too?
Go ahead. Are you going to reformat them for legibility first, if necessary? Are you going to personally decide, in *your* opinion, what's worth forwarding and what isn't? Are you going to be topical? More to the point, Declan, are you going to do it in such a way that the residents of the list actually *use* in further discussion? Or are you going to do it to "prove" that, reductio ad absurdum, *any* forwards are equivalent to *all* forwards? I thought not. Hey, I got an idea, myself. Let's just close down the list and do it *all* on the web? Maybe CNET can stick pop-up ads in our faces for the privilege, Declan an up his click-count, and CNET will send him to the Black Rock Desert, or Bora-Bora, or the Crimea, or wherever, for some conference or other. Or a Senate hearing. Or whatever. I mean, who needs that pesky 'd' key, anyway? In the meantime, Declan, own *these* words: don't be a putz. Cheers, RAH -----BEGIN PGP SIGNATURE----- Version: PGP 8.0.3 iQA/AwUBQSNXn8PxH8jf3ohaEQJwTQCg+hpBwCoGQryuoJAdyYP4awO3nDYAoLKa UKwhmMOEdC2q2yA/JLjIbFuV =fO4K -----END PGP SIGNATURE----- -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
On Wed, 18 Aug 2004, Declan McCullagh wrote:
At 01:02 AM 8/18/2004, J.A. Terranson wrote:
Since when is on-topic crossposting an issue here?
Since forever. Since before either of us joined the list (and I first started reading a decade ago).
It's a matter of politeness and degree. A pointer to a discussion archived on the web is more useful than dozens of forwarded messages.
Hey, I have an idea! Why don't I write a script crossposting everything from sci.crypt to cypherpunks! How about a few dozen other "on-topic" newsgroups and mailing lists too?
We're not talking about just sci.crypt chatter here, he has been forwarding posts on one of the single most interesting (to anyone crypto-inclined) topics in *years*. And not everyone (crypto-inclined or not) subs to all of the many sources: if you want to get the word out to the less than hard-core, this list is a great starting point. You complaints on this appear (based mostly on your banter with RAH) to be more a personal problem than anything else. Perhaps you should step back and look at the big picture here?
-Declan
-- Yours, J.A. Terranson sysadmin@mfn.org 0xBD4A95BF "...justice is a duty towards those whom you love and those whom you do not. And people's rights will not be harmed if the opponent speaks out about them." Osama Bin Laden - - - "There aught to be limits to freedom!" George Bush - - - Which one scares you more?
At 10:03 PM -0500 8/17/04, Declan McCullagh wrote:
Sigh. RAH has descended to the level of a net.kook.
Never would have guessed.
You've exactly the same used the same rhetorical device twice now. Are you just lazy, or, more likely, have you just peaked too soon? How does it feel to be someone whose best years are a decade behind him, Declan? You are *sooo* boring. RAH -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
...and another thing... At 7:33 PM -0500 8/17/04, Declan McCullagh wrote:
-Declan "TCM" McCullagh
Does this mean you spend all day in a Barcolounger dry-jacking a Mossberg, muttering about Janet Reno? ;-) Cheers, RAH "Banks in Hong Kong and Shanghai", indeed... -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
participants (4)
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David Honig
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Declan McCullagh
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J.A. Terranson
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R. A. Hettinga