nanog mailing list archives
Re: SHA1 collisions proven possisble
From: "Patrick W. Gilmore" <patrick () ianai net>
Date: Thu, 23 Feb 2017 20:56:28 -0500
On Feb 23, 2017, at 6:21 PM, valdis.kletnieks () vt edu wrote:
On Thu, 23 Feb 2017 17:40:42 -0500, "Ricky Beam" said:cost! However this in no way invalidates SHA-1 or documents signed by SHA-1.We negotiate a contract with terms favorable to you. You sign it (or more correctly, sign the SHA-1 hash of the document). I then take your signed copy, take out the contract, splice in a different version with terms favorable to me. Since the hash didn't change, your signature on the second document remains valid. I present it in court, and the judge says "you signed it, you're stuck with the terms you signed". I think that would count as "invalidates documents signed by SHA-1", don't you?
Doesn’t work that way. According to the blog post, you can create two documents which have the same hash, but you do not know what that hash is until the algorithm finishes. You cannot create a document which matches a pre-existing hash, i.e. the one in the signed doc. Hence my comment that you can’t take Verisign’s root key and create a new key which matches the hash. -- TTFN, patrick
Current thread:
- Re: SHA1 collisions proven possisble, (continued)
- Re: SHA1 collisions proven possisble Ricky Beam (Feb 23)
- Re: SHA1 collisions proven possisble J. Hellenthal (Feb 23)
- Re: SHA1 collisions proven possisble Royce Williams (Feb 23)
- Re: SHA1 collisions proven possisble Richard Hesse (Feb 25)
- Re: SHA1 collisions proven possisble valdis . kletnieks (Feb 25)
- Re: SHA1 collisions proven possisble Randy Bush (Feb 26)
- Re: SHA1 collisions proven possisble valdis . kletnieks (Feb 23)
- Re: SHA1 collisions proven possisble Jon Lewis (Feb 23)
- Re: SHA1 collisions proven possisble valdis . kletnieks (Feb 23)
- Re: SHA1 collisions proven possisble Vincent Bernat (Feb 24)
- Re: SHA1 collisions proven possisble Patrick W. Gilmore (Feb 23)
- Re: SHA1 collisions proven possisble valdis . kletnieks (Feb 23)
- Re: SHA1 collisions proven possisble Patrick W. Gilmore (Feb 23)
- Re: SHA1 collisions proven possisble Vincent Bernat (Feb 24)
- Re: SHA1 collisions proven possisble Patrick W. Gilmore (Feb 24)
- Re: SHA1 collisions proven possisble Ricky Beam (Feb 23)
- Re: SHA1 collisions proven possisble valdis . kletnieks (Feb 23)
- RE: SHA1 collisions proven possisble David Edelman (Feb 23)
- Re: SHA1 collisions proven possisble Lyndon Nerenberg (Feb 23)
- Re: SHA1 collisions proven possisble Florian Weimer (Feb 24)
- Re: SHA1 collisions proven possisble Jimmy Hess (Feb 25)