On 1/12/2011 11:24 AM, Daniel Kahn Gillmor wrote: > "look -- here is Mr. X claiming that he is going to poison the > reservoir. Please take this seriously, and note that it could only have > come from Mr. X because it is signed with his key."
Mr. X has a conspirator, Ms. Y. Mr. X deliberately avoids installing an OS patch so that Ms. Y can pwn the box. Now that you've made this accusation against Mr. X, Mr. X reveals "hey, my box was cracked! I've been rooted and I've been sending out signed emails without my knowledge! How /dare/ you impugn me without having all the facts!" Or, a less contrived example: imagine that Mr. X is a stockbroker. He conspires with Ms. Y to pwn the box. You receive a signed message from Mr. X saying, "I want to buy 1000 shares of Yoyodyne from you at $10/share." On the basis of this, you send him 1000 shares. Yoyodyne immediately tanks. A week later Mr. X returns. "Hi, I was off in Bali on a beach sipping mai tais. Anything interesting happen while I was gone? What the heck? My box got pwn3d! I didn't place that order! Ack! I'm so sorry about this. Here, take your 1000 shares back, and I'll take my $10,000 back." (Of course, if Yoyodyne had gone up in value, Mr. X would not have repudiated the signature.) OpenPGP's nonrepudiability is largely a myth. I have never seen it tested in court. Given the fragility of our computer systems and how easily they're compromised, I think it's worthwhile to be very skeptical of any analysis that's predicated on nonrepudiability. _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
