Courts have "experts".  You just need one that understands bitcoin and can testify that he knows that including the hash retroactively isn't possible.  The other party's expert won't be able to claim otherwise without perjuring himself, and any math teacher or computer science professor from a local college will be able to back your guy up on the tricky parts (hashing), even if he doesn't know bitcoin specifically.

Oh, but keep in mind that the timestamps aren't exact.  There is a several hour window on either side.  That is enough for most things, but not enough for precision timing.

I didn't wait to see if it would be accepted in court: https://bt.irlbtc.com/view/39548.msg519255#msg519255 

You can present it as evidence with an expert witness, whether a jury will get it is another story.

is this implemented anywhere? the paper blows my brains out just by looking at it.

The point is it could have been manipulated before hashing.

For the purpose of documenting the fact that damage occurred before a certain time this technique works just fine.  The other side would have to argue that you photoshopped up some fake damage intending to do the actual damage later.

It's evidence of Transactions occurring between addresses. Period.

To explain the intent or purpose of those transactions is a different story.

Can it be done, sure. But if LE is at that stage in investigating, they don't need the blockchain. It will just be another aspect of proof.

Think of how hard that is. Even if you prove that TX1 went to TX2, WHO sent TX1 and WHO received it and for what purpose. And now this gets even more complicated because the route from TX1 to TX2 may have thousands of transmissions between them.

Then you have the encrypted transfer of wallet.dat files containing an amount of BTC which would bypass miners and fees. I.E. There will be 21 Million BTC. Now imagine 21 Million Wallet.dat files being transferred to others bypassing miners all together. And the method of transfer doesn't even need to be electronic.

Not to mention that if it becomes accepted, people could send BTC to someone to implicate them in something that they had nothing to do with. Or cause them headaches.

For Example: PP customers send PP's CEO a $1 with a note: Thanks for the BitCoins   The PP CEO would be wrongly assumed to have violated his own companies policies. (But that wouldn't be fair or correct)

However there is a good point here:

The qt client allows the viewing of Transmissions and Receipts whether the wallet.dat is encrypted or not. This, IMO, is a privacy and security flaw. Anyone with access to the program could view your personal financial transactions.

To me this is akin to allowing everyone to see your online banking account details but they aren't allowed to transfer anything. If and until this is fixed, I would suggest for any serious and private TX to use the program from an encrypted disk and/or folder.

I'm sure I'm wrong about something, correct if necessary.

commitcoin isn't my idea, to clarify. I'll just do the implementation, since there isn't one yet, as far as I can tell.

@BTC_bear very interesting questions, thought provoking. I'd start with a claim that private keys are secrets and that TX1 and TX2 could only be initiated by a person(s) with knowledge of the keys to sign ... and here are the keys.