[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Gnu-arch-users] Re: MD5 is broken
From: |
Karel Gardas |
Subject: |
Re: [Gnu-arch-users] Re: MD5 is broken |
Date: |
Wed, 16 Mar 2005 12:46:28 +0100 (CET) |
On Wed, 16 Mar 2005, Peter Conrad wrote:
> Am Mittwoch, 16. M?rz 2005 11:51 schrieb Karel Gardas:
> > On Wed, 16 Mar 2005, Peter Conrad wrote:
> > > Hi,
> > >
> > > On Wed, Mar 16, 2005 at 12:26:30PM +0600, Ivan Boldyrev wrote:
> > > > Tom Lord merges sexy patch. Even if he will re-sign patch,
> > > > MD5 sum in ./checksum will be same because *.patches.tar.gz is same.
> > >
> > > this is wrong. If Tom merges your patch, he will automatically create
> > > additional log entries in his own branch. This (among other things, like
> > > changed timestamps) will lead to a file with a different MD5 sum.
> >
> > I'm afraid the whole message is a bit different: hack the mirror, hack the
> > patch while keeping MD5 intack and let your attack to software X spread
> > thorough the world.
>
> I understood Ivan's scenario like this:
[...]
Sorry! That's just my short-cut of the whole problem. As I've already
written I don't agree fully with Ivan's statements, but this does not
change anything on the fact that MD5 is broken.
> > I've just now looked at tla and baz and found that at least mirror on:
> > http://bazaar.canonical.com/archives/address@hidden/ uses also
> > SHA-1 hashes. Since SHA-1 is also considered weak these days, this
> > does not add that much security, but certainly at least something
> > before arch move to some more secure hash implementation.
>
> Combining different hashes in the signature should make attacks a lot
> more difficult, because an attacker would have to produce collisions
> for all hashes at the same time. Of course, *all* hashes must be
> validated when checking the signature, instead of validating only one
> of them.
Yes, I agree, but combining two hashes from which one is considered broken
and one is considered weak these days is IMHO less secure than using one
hash which is considered secure.
Cheers,
Karel
--
Karel Gardas address@hidden
ObjectSecurity Ltd. http://www.objectsecurity.com
- Re: [Gnu-arch-users] Re: MD5 is broken, (continued)
- Re: [Gnu-arch-users] Re: MD5 is broken, Jan Hudec, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Tom Lord, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Karel Gardas, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Tom Lord, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Matthew Dempsky, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Andrew Suffield, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Karel Gardas, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Peter Conrad, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Karel Gardas, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Peter Conrad, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken,
Karel Gardas <=
- Re: [Gnu-arch-users] Re: MD5 is broken, Jason McCarty, 2005/03/16
- [Gnu-arch-users] Re: MD5 is broken, Matthieu Moy, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Adrian Irving-Beer, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, John Arbash Meinel, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Adrian Irving-Beer, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, John Arbash Meinel, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Aaron Bentley, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, John Arbash Meinel, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, Aaron Bentley, 2005/03/16
- Re: [Gnu-arch-users] Re: MD5 is broken, John Arbash Meinel, 2005/03/16