Re: PlayStation 3 predicts next US president

2007-12-14 Thread John Levine
The financial industry has actually created its own system - I forget the name, some like a Gold Bond Certification - that it requires for certain high-importance transactions (e.g., a document asserting you own some stock for which you've lost the certificates). That's a medallion signature

Re: PlayStation 3 predicts next US president

2007-12-13 Thread Ed Gerck
Allen wrote: William Allen Simpson wrote: [snip] The whole point of a notary is to bind a document to a person. That the person submitted two or more different documents at different times is readily observable. After all, the notary has the document(s)! No, the notary does not have the

Re: PlayStation 3 predicts next US president

2007-12-13 Thread Leichter, Jerry
| The whole point of a notary is to bind a document to a person. That | the person submitted two or more different documents at different | times is readily observable. After all, the notary has the | document(s)! | | No, the notary does not have the documents *after* they are notarized, |

Re: PlayStation 3 predicts next US president

2007-12-13 Thread James A. Donald
William Allen Simpson wrote: The whole point of a notary is to bind a document to a person. That the person submitted two or more different documents at different times is readily observable. After all, the notary has the document(s)! The notary does not want to have the documents, or to

Re: PlayStation 3 predicts next US president

2007-12-13 Thread Florian Weimer
* William Allen Simpson: Assuming, Dp := any electronic document submitted by some person, converted to its canonical form Cp := a electronic certificate irrefutably identifying the other person submitting the document Cn := certificate of the notary Tn := timestamp

Re: PlayStation 3 predicts next US president

2007-12-11 Thread Allen
William Allen Simpson wrote: [snip] The whole point of a notary is to bind a document to a person. That the person submitted two or more different documents at different times is readily observable. After all, the notary has the document(s)! No, the notary does not have the documents

Re: PlayStation 3 predicts next US president

2007-12-11 Thread silky
On Dec 11, 2007 5:06 AM, Allen [EMAIL PROTECTED] wrote: What puzzles me in all this long and rather arcane discussion is why isn't the solution of using a double hash - MD5 *and* SHA whatever. The odds of find a double collision go way up. Some open source software people are already doing

Re: PlayStation 3 predicts next US president

2007-12-10 Thread James A. Donald
William Allen Simpson wrote: The notary would never sign a hash generated by somebody else. Instead, the notary generates its own document (from its own tuples), and signs its own document, documenting that some other document was submitted by some person before some particular

Re: PlayStation 3 predicts next US president

2007-12-10 Thread William Allen Simpson
Francois Grieu wrote: That's because if Tn is known (including chosen) to some person, then (due to the weakness in MD5 we are talking about), she can generate Dp and Dp' such that S( MD5(Tn || Dp || Cp || Cn) ) = S( MD5(Tn || Dp' || Cp || Cn) ) whatever Cp, Cn and S() are. First of all, the

Re: PlayStation 3 predicts next US president

2007-12-09 Thread James A. Donald
William Allen Simpson wrote: The notary would never sign a hash generated by somebody else. Instead, the notary generates its own document (from its own tuples), and signs its own document, documenting that some other document was submitted by some person before some particular time. And

Re: PlayStation 3 predicts next US president

2007-12-09 Thread William Allen Simpson
Personally, I thought this horse was well drubbed, but the moderator let this message through, so he must think it important to continue James A. Donald wrote: William Allen Simpson wrote: The notary would never sign a hash generated by somebody else. Instead, the notary generates its

Re: PlayStation 3 predicts next US president

2007-12-05 Thread dan
If on the one hand, the correct procedure is sign-encrypt-sign, then why, on the other hand, is the parallel not sign-hash-sign ? --dan = http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.ps Donald T. Davis, Defective Sign Encrypt in S/MIME, PKCS#7, MOSS, PEM, PGP, and XML.,

Re: PlayStation 3 predicts next US president

2007-12-03 Thread William Allen Simpson
James A. Donald wrote: Not true. Because they are notarizing a signature, not a document, they check my supporting identification, but never read the document being signed. This will be my last posting. You have refused several requests to stick to the original topic at hand. Apparently,

Re: PlayStation 3 predicts next US president

2007-12-03 Thread William Allen Simpson
Weger, B.M.M. de wrote: See http://www.win.tue.nl/hashclash/TargetCollidingCertificates/ ... Our first chosen-prefix collision attack has complexity of about 2^50, as described in our EuroCrypt 2007 paper. This has been considerably improved since then. In the full paper that is in preparation

Re: PlayStation 3 predicts next US president

2007-12-03 Thread Allen
William Allen Simpson wrote: [snip] Actually, I deal with notaries regularly. I've always had to physically sign while watched by the notary. They always read the stuff notarized, and my supporting identification, because they are notarizing a signature (not a document). And yes, they

Re: PlayStation 3 predicts next US president

2007-12-02 Thread William Allen Simpson
James A. Donald wrote: This attack does not require the certifier to be compromised. You are referring to a different page (that I did not reference). Never-the-less, both attacks require the certifier to be compromised! The attack was to generate a multitude of predictions for the US

Re: PlayStation 3 predicts next US president

2007-12-02 Thread William Allen Simpson
Weger, B.M.M. de wrote: The parlor trick demonstrates a weakness of the pdf format, not MD5. I disagree. We could just as easy have put the collision blocks in visible images. Parlor trick. ... We could just as easy have used MS Word documents, or any document format in which there is some

RE: PlayStation 3 predicts next US president

2007-12-02 Thread Weger, B.M.M. de
Hi William, ... We say so on the website. We did show this hiding of collisions for other data formats, such as X.509 certificates More interesting. Where on your web site? I've long abhorred the X.509 format, and was a supporter of a more clean alternative. See