Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-29 Thread R. A. Hettinga
At 11:49 AM -0800 12/28/03, Jim Gillogly wrote: wouldn't it be preferable to prove that you've contributed the same amount of power to a useful compute-bound project, such as NFSNET.org or GIMPS or [EMAIL PROTECTED] or [EMAIL PROTECTED] Simple economics. If you're going to go so far as using some

Re: Non-repudiation (was RE: The PAIN mnemonic)

2003-12-29 Thread Ben Laurie
Amir Herzberg wrote: Ian proposes below two draft-definitions for non-repudiation - legal and technical. Lynn also sent us a bunch of definitions. Let's focus on the technical/crypto one for now - after all this is a crypto forum (I agree the legal one is also somewhat relevant to this forum).

Re: Non-repudiation (was RE: The PAIN mnemonic)

2003-12-29 Thread Ben Laurie
Carl Ellison wrote: If you want to use cryptography for e-commerce, then IMHO you need a contract signed on paper, enforced by normal contract law, in which one party lists the hash of his public key (or the whole public key) and says that s/he accepts liability for any digitally signed

Re: Non-repudiation (was RE: The PAIN mnemonic)

2003-12-29 Thread Ben Laurie
Carl Ellison wrote: -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Stefan Kelm Sent: Tuesday, December 23, 2003 1:44 AM To: [EMAIL PROTECTED] Subject: Re: Non-repudiation (was RE: The PAIN mnemonic) Ah. That's why they're trying to rename the

Re: Non-repudiation (was RE: The PAIN mnemonic)

2003-12-29 Thread Ben Laurie
Amir Herzberg wrote: At 04:20 25/12/2003, Carl Ellison wrote: ... If you want to use cryptography for e-commerce, then IMHO you need a contract signed on paper, enforced by normal contract law, in which one party lists the hash of his public key (or the whole public key) and says that

Re: Repudiating non-repudiation

2003-12-29 Thread Jerrold Leichter
Ian's message gave a summary that's in my accord with how courts work. Since lawyers learn by example - and the law grow by and example - here's a case that I think closely parallels the legal issues in repudiation of digital signature cases. The case, which if I remember right (from hearing

Re: I don't know PAIN...

2003-12-29 Thread Matt Crawford
On Dec 27, 2003, at 10:01 AM, Ben Laurie wrote: Note that there is no theoretical reason that it should be possible to figure out the public key given the private key, either, but it so happens that it is generally possible to do so So what's this generally possible business about? Well, AFAIK

Re: Ousourced Trust (was Re: Difference between TCPA-Hardware and a smart card and something else before

2003-12-29 Thread Rich Salz
I asked the guy making the presentation about the similarity to Kerberos message flows and he said something to the effect of ah yes, kerberos. Not sure what the guy meant by that. But yes, SAML flows are just like Kerberos flows. And Liberty and WS-Federation look a lot like DCE cross-cell

Re: I don't know PAIN...

2003-12-29 Thread Jerrold Leichter
| Note that there is no theoretical reason that it should be | possible to figure out the public key given the private key, | either, but it so happens that it is generally possible to | do so | | So what's this generally possible business about? | | Well, AFAIK its always possible, but I

Re: Ousourced Trust (was Re: Difference between TCPA-Hardware and a smart card and something else before

2003-12-29 Thread Anne Lynn Wheeler
On Mon, 2003-12-29 at 10:16, Rich Salz wrote: Not sure what the guy meant by that. But yes, SAML flows are just like Kerberos flows. And Liberty and WS-Federation look a lot like DCE cross-cell (er, Kerberos inter-realm) flows. After all, there's only not many ways to do secure online

Re: Repudiating non-repudiation

2003-12-29 Thread robin benson
On 29 Dec 2003, at 19:29, Paul A.S. Ward wrote: This first case is actually quite amusing. I was recently the subject of identity theft. Specifically, the thieves had my SSN (SIN, actually, since it is in Canada), and my driver's licence number. They produced a fake driver's licence, and

Re: I don't know PAIN...

2003-12-29 Thread Eric Rescorla
Jerrold Leichter [EMAIL PROTECTED] writes: | Note that there is no theoretical reason that it should be | possible to figure out the public key given the private key, | either, but it so happens that it is generally possible to | do so | | So what's this generally possible business

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-29 Thread Bill Stewart
At 09:37 PM 12/26/2003 -0500, Adam Back wrote: The 2nd memory [3] bound paper (by Dwork, Goldber and Naor) finds a flaw in in the first memory-bound function paper (by Adabi, Burrows, Manasse, and Wobber) which admits a time-space trade-off, proposes an improved memory-bound function and also in

Re: Difference between TCPA-Hardware and a smart card (was: example: secure computing kernel needed)

2003-12-29 Thread bear
On Tue, 23 Dec 2003, Seth David Schoen wrote: When attestation is used, it likely will be passed in a service like HTTP, but in a documented way (for example, using a protocol based on XML-RPC). There isn't really any security benefit obtained by hiding the content of the attestation _from the

Re: I don't know PAIN...

2003-12-29 Thread Jerrold Leichter
| On Dec 27, 2003, at 10:01 AM, Ben Laurie wrote: | Note that there is no theoretical reason that it should be possible | to figure out the public key given the private key, either, but it so | happens that it is generally possible to do so | So what's this generally possible business about? |

Re: example: secure computing kernel needed

2003-12-29 Thread David Wagner
Jerrold Leichter wrote: | *Any* secure computing kernel that can do | the kinds of things we want out of secure computing kernels, can also | do the kinds of things we *don't* want out of secure computing kernels. David Wagner wrote: | It's not hard to build a secure kernel that doesn't provide

Re: Difference between TCPA-Hardware and a smart card (was: example: secure computing kernel needed)

2003-12-29 Thread David Wagner
Rick Wash wrote: There are many legitimate uses of remote attestation that I would like to see. For example, as a sysadmin, I'd love to be able to verify that my servers are running the appropriate software before I trust them to access my files for me. Remote attestation is a good technical

Re: example: secure computing kernel needed

2003-12-29 Thread David Wagner
Ed Reed wrote: There are many business uses for such things, like checking to see if locked down kiosk computers have been modified (either hardware or software), I'm a bit puzzled why you'd settle for detecting changes when you can prevent them. Any change you can detect, you can also prevent