Hash escrow(pdf23ds.net) |
Hash escrow(pdf23ds.net) |
http://en.wikipedia.org/wiki/Trusted_timestamping
A personal favorite which I highly recommend is the following:
http://www.itconsult.co.uk/stamper.htm
Under normal circumstances, one would need an expert witness to authenticate the signature, but in several jurisdictions which enacted digital signature laws statues, that may not be necessary depending on the evidentiary status of e-signatures.
http://www.win.tue.nl/hashclash/Nostradamus/
In November 2007, they posted the MD5 hash of a PDF file containing the name of the winner of the 2008 election. That of course doesn't prove that they knew who would win the election, because they prepared 12 different PDFs with 12 different names in it, all of which were crafted to generate the same MD5 hash. I don't think the hypothetical jury is going to like it.
Okay, let's try again with SHA256...
It also assumes that twitter is going to be around when you finally need the timestamped hashes, and that you can prove that twitter (or any other service for that matter) can't have back-dated hashes inserted.
Posting to a usenet group, like alt.test, where independent systems store and timestamp the message would be a better idea.
Oh, if only. Digital evidence is seeing a lot more acceptance in recent years - but just recently there has been a sudden resistance to it, partly, I think, because of all the noise being made in the media about the ease of faking such things and the prevalence of viruses.
Oftentimes an audio recording tagged to within a couple of days will be fine.
But don't rely on that - it could easily be rejected out of hand by a judge who is not convinced.
Any sort of ambiguity in digital evidence and timestamps is being frowned on at the moment - at least here in the UK.