Re: Synful Knock questions...

[Jake Mertel <jake.mertel () ubiquityhosting com>]

My apologies, Valdis is indeed correct, I did not mean to suggest that it
would be possible to make modifications in such a way that would result in
an identical checksum. Sorry for the confusion and extra noise.



--
Regards,

Jake Mertel
Ubiquity Hosting



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On Tue, Sep 15, 2015 at 1:01 PM, <Valdis.Kletnieks () vt edu> wrote:

> On Tue, 15 Sep 2015 11:54:30 -0700, Jake Mertel said:
> > Indeed -- While there are methods that can be used to "pack" a file so
> that
> > it collides with a desirable checksum, that would be nearly impossible to
> > do in this scenario.
>
> Small clarification here.
>
> There are known methods to easily produce two files that have the same MD5
> hash, but you have no control over the checksum.
>
> There are not (to my knowledge) ways to tweak a file to produce a specified
> MD5 hash.  MD5 is broken, but not *that* broken (yet).  Feel free to point
> me at papers if it's been done.
>
> There are ways to easily produce a file with a specified
> non-crypto-strength
> hash like a CRC-32.
>
> So it really matters to be clear on what algorithm is used for the
> checksum/hash.