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.
Topic: use blockchain for proof in court? - page 2. (Read 2476 times)
Can I put a hash of a photo into the blockchain and use it later in court to prove that particular photo was taken before time x?
You can prove that particular image existed before the block was added to the blockchain. However, there is no way to prove the image was not manipulated with tools like Photoshop.
http://en.wikipedia.org/wiki/Cryptographic_hash_function
is this implemented anywhere? the paper blows my brains out just by looking at it.
You can prove that particular image existed before the block was added to the blockchain. However, there is no way to prove the image was not manipulated with tools like Photoshop.
I'm sure court investigators have had many chances to hone their photoshop detection skills these past two decades.
You can present it as evidence with an expert witness, whether a jury will get it is another story.
ha! actually, that was exactly what I had in mind. I'm currently moving into an office and a window is damaged. I wanna be able to prove it happened before my time there
@OP: expert witness is all you need
@Frozenlock: Love that link. Sending yourself sealed "original work" like screenplay before going to Hollywood to show it to local copyright whores is so 20st century.
@Frozenlock: Love that link. Sending yourself sealed "original work" like screenplay before going to Hollywood to show it to local copyright whores is so 20st century.
I didn't wait to see if it would be accepted in court: https://bitcointalksearch.org/topic/m.519255 
Can I put a hash of a photo into the blockchain and use it later in court to prove that particular photo was taken before time x?
You can prove that particular image existed before the block was added to the blockchain. However, there is no way to prove the image was not manipulated with tools like Photoshop.
You can put the hash in the blockchain and prove it was taken before that block was generated. It would be good proof to me, but proving the timestamp of that block and what your hash proves would likely be "interesting" in court. That's a lot of math you'd have to explain to a jury.
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.
You can put the hash in the blockchain and prove it was taken before that block was generated. It would be good proof to me, but proving the timestamp of that block and what your hash proves would likely be "interesting" in court. That's a lot of math you'd have to explain to a jury.
Can I put a hash of a photo into the blockchain and use it later in court to prove that particular photo was taken before time x?
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