Prove the existence of documents using the Blockchain

[GreatArkansas]

Look at this, these two lovely couples got married without lawyer/notary needed.
It is only needed bitcoin blockchain to certify their marriage.



Amazing, isn't it?

This is my first time to saw that you can do this, you can prove the existence of some documents you have using the Bitcoin blockchain.
The good thing here is you don't depend or need to rely on or trust some centralized entity. The existence of your documents is permanently validated by the blockchain.

They called this Proof Of Existence, the original Blockchain notary service, offering instant, anonymous, distributed, and secure proof of existence for any document, agreement, or contract.
Common Uses:

• Certify the existence of your document without the need of a central authority.
• Useful for copyrighted material
• Useful for patents
• Checking for document integrity.

The process of proving the existence of this document requires 3 steps :

• Create a unique hash representing the document
• Preparing a transaction to write the hash in the blockchain
• Get the fee and process the transaction

You can check it out on this website Proof Of Existence.

Any some best cases or situation that we can use this?
And do you know some website can do this or tutorial how we can do it by ourself only?

[dkbit98]

I saw this, and it is interesting, but I dont think that every country will accept this
as a legal way of confirming marriage.

[tbct_mt2]

It is another step, another usecase of blockchain technology in order to bring blockchain more existing and more widely used in real life. The whole crypto market should not solely depend upon bitcoin, and dominate by bitcoin developments. We need to see more innovations in blockchain industry, like this one. It looks crazy, and illegal, but yeah it is another usecase of blockchain.
Honestly, I don't have reason to use this for my marriage certificate, because with or without it, if I feel happy with the girl I live with, I don't need paper-based or blockchain-based certificate. Living with her, together, happily is enough.

[DdmrDdmr]

It’s an interesting (partial) alt case of use for the BTC blockchain. Specifically, in for those similar solutions that are BTC blockchain based, what goes on behind the scenes is as follows:

The document is certified via embedding its SHA256 digest in the Bitcoin Blockchain. This is done by generating a special Bitcoin transaction that encodes/contains the hash via an OP_RETURN script. This is a Bitcoin scripting opcode that marks the transaction output as provably un-spendable and allows a small amount of data to be inserted, which in our case is the document’s hash, plus a marker to identify all of our transactions.(1)

Basically, you upload a file (see (2)) and get a unique hash derived from the content and the timestamp. That hash is meant to be the proof that, on a certain date, you were in possession of the document you hashed. The hash is uploaded to the BTC blockchain (obviously not the document itself), constituting a decentralized proof of the existence of the document.

What remains to be seen is just how extended this kind of solution is being accepted in legal processes that require proof of ownership of a given document, and how that acceptance breaks down by country.

There are multiple services of the kind (proofofexistence, poex, stampery, factom, originstamp, etc.), although some use private blockchains to store the data such as factom.

See:
(1)https://www.newsbtc.com/proof-of-existence/
(2)https://medium.com/@kiknaio/what-is-proof-of-existence-and-how-will-it-help-to-protect-intellectual-or-private-property-77aa97a3fbb1

[Pffrt]

And do you know some website can do this or tutorial how we can do it by ourself only?

You can do it with www.deepvaultonline.com, DeepVault, a product of DeepOnion. The cost is around $0.001/per file, with registering in the deepvaultonline, you can get 15 credits for free.

[Coding Enthusiast]

Any some best cases or situation that we can use this?
And do you know some website can do this or tutorial how we can do it by ourself only?

What this really is, is a method of inserting any kind of raw data in an immutable, decentralized and public ledger. This "data" can be anything you want because bitcoin doesn't care about the content of this special output. It is known as OP_RETURN outputs.

The way to do it is as simple as creating a new output with 0x6a or OP_Return and follow that up with a push of your data up to the specified maximum size.

Now that we've defined it, we can come up with use cases:
- Plain text
Example transaction
6a-13-636861726c6579206c6f766573206865696469 = <OP_Return> <PushData> charley loves heidi

- Hash of documents
You've already provided an example for documents. Another real world example is the government of Georgia that have been using bitcoin's blockchain for land registry with the help of Bitfury ever since 2016.

- Omni layer
https://github.com/OmniLayer/spec
https://medium.com/omnilayer/optimizing-the-payloads-of-omni-layer-transactions-ccb0a867da5d

- Mining altcoins!
I believe it is called Proof-of-Proof and is what Veriblock is using.

- Server-less & domain-less websites
This is a combination of torrents and bitcoin blockchain. https://github.com/elendirx/web2web

- TLS Certificates
A more advanced version of X.509 infrastructure using bitcoin's blockchain and OP_Return outputs for revocation of certificates and self-signed certificates
https://github.com/ChristopherA/revocable-self-signed-tls-certificates-hack

This article has some statistical information about OP_Return cases: https://www.researchgate.net/publication/313365747_An_analysis_of_Bitcoin_OP_RETURN_metadata

[GreatArkansas]

~~
There are multiple services of the kind (proofofexistence, poex, stampery, factom, originstamp, etc.), although some use private blockchains to store the data such as factom.

I'm curious on the fees, I saw on proofofexistence, the fee is fixed, 0.00025. It is not the fee you will paid for miners,
I am a little bit curious, what will happen the 0.00025btc?
Does ProofOfExistence will get some in those amount?

What this really is, is a method of inserting any kind of raw data in an immutable, decentralized and public ledger. This "data" can be anything you want because bitcoin doesn't care about the content of this special output. It is known as OP_RETURN outputs.

I see it is really amazing since the public ledger will never restrict what will be the data since the document is being hashed.
I also read about it, about the document integrity.

If you store a proof for your document and later re-upload it, the system will only recognize it if it is completely and fully the same document. The slightest change, and we'll recognize it is different, giving you the security that certified data can't be changed.

Once the hash will be the same or document will be the same as the uploaded, the system will notice it.