The block chain of Bitcoin offers its users the innovative feature of decentralized, trust-less timestamping (or blockstamping* as I prefer to call it). That may not sound like much, but it heralds a new era when anyone can cheaply create an unforgeable proof-of-existence of any document.
However, this idea is still in its infancy. Most services use the “OP_RETURN” space available in every bitcoin transaction (it’s kinda like a row for comments) and there is no requirement on nodes to save that part of each bitcoin transaction in their copy of the blockchain. Anyone who has to be sure his/her comment can be found/verified in the future also need to keep their own “full” copy of the blockchain, alongside the data from the timestamp – and the document/documents in question. There are other more clever ways of timestamping, though, using the built-in solution multisig or creating a Merkle Tree root, like Tierion does.
Through using a Merkle tree root, for instance with an API like Tierion it’s possible to timestamp thousands or millions of documents with only one bitcoin transaction (a Merkle Tree in practice works like a cryptographic “trail” of sorts, containing hashes corresponding to a large number of documents). You do need to expend some processing power to create all those hashes though.
The Proof Is In The (Blockchain) Pudding
In any case it’s easy to generate a Bitcoin-compatible and unique hash from any document. After blockstamping that document’s hash with a transaction on the Bitcoin network it can easily be verified cryptographically. In practice timestamping can create a new avenue for artists, innovators, rights managers, inventors, designers, lawyers, engineers, software developers, brand managers and just about anybody to securely create an indisputable proof in time that the document in question existed.
Several services and platforms are incorporating this feature of the Bitcoin network, among them:
Proof-of-existence proves the concept in a simple way and is a fully functioning one-page-service to quickly timestamp any digital document. Just drag and drop the document you want to blockstamp in the Bitcoin network onto the box on this page and you’ll receive a unique hash in return. And if you’ve already timestamped the document in question Proof-of-existence.com will tell you that when dropping your asset onto their hash solution.
Save that hash and its transaction id (“the txid”) as it can be used at a later date to prove that you blockstamped that document at the particular time of the next block confirmation (where the transaction with your unique hash is included).
Each blockstamp takes approx. 10 minutes to confirm, after paying 5 millibits (5000 bits, or 0.005 bitcoins) – or longer if there is a queue of other transactions with a higher fee attached.
The image of me, myself and I (on the right) is timestamped into the blockchain in block number 402459 (2016-03-13 11:11:59). The name of the file is “nanok-inspekterar-gruvan.jpg”. Anyone may now independently confirm the timestamp in question, constituting an indisputable proof the image existed at this particular point in time.
Tierion has garnered a lot of attention for their simple-to-use API and its connection to lots of other online services (to “slingshot” your blockchained data to other services). They also offer a tool to allow people to easily and quickly verify “receipts” of timestamped docs, and make use the most secure blockchain (Bitcoin’s).
– We’re building a verification node called Checkpoint that anyone can download and run, says Tierion founder Wayne Vaughan. Competitors such as Factom try to lock you into their platform by creating their own blockchain and altcoin. You have to acquire their special token or use a middleman to write data to the Factom blockchain.
Using Tierion the data can be stored anywhere – even in another decentralized datastore. There is no long-term dependency on Tierion.
Industry-specific timestamping services
Blocksign doubles up on functionality; in addition to timestamping contracts or other documents this service also lets its users send invoices.
Blockverify specializes in providing provenance on real-world stuff like diamonds and electronics.
Bitproof is another solution to the same problem, and they offer a centralized add-on solution where you can add an account with a password, sign it with a video of yourself and if you lose your records Bitproof can find your registration at a later date.
There are many other services using this functionality of the Blockchain in development worldwide, including a student project called Astroblock. Their target is the scientific community (the document and its hash is also sent to a group of experts for peer review).
Monegraph used to offer artists a specialized way to prove ownership of works of art using the Blockchain, but have pivoted towards offering of platform to help artists monetize their works, regardless of any blockchain tech running in the background.
Expect lots of services, brands and companies to announce their own “blockchain provenance” going forward. But, until they (anyone of them) have enough users (network effect) it’ll be a fragmented market and most of these announcements are more intended to raise VC or just create PR.
This field should disrupt and transform the intellectual property rights landscape (but it’ll take years, as most systems also depend on “real-world-law” to be of any use), so watch this page for more links to new contenders maturing in this space (such as BitID and BTProof).
NOTE: There is a “myth” circulating on this subject; that any plain text timestamped (blockstamped) in the Blockchain will stay there forever. Actually, there are no requirements placed on nodes to save those messages. Only the transactional hashes are saved. Also, the actual document is never saved into the Blockchain, just the unique cryptographic hash of the document in question. So – older plain-text URL:s entered into the Blockchain at an earlier date have mostly disappeared from nodes not bothering with saving all of the OP_CODES (the space most of these services use to register your hash). The transactional hashes remain, though, forever and ever (as long as the Bitcoin Blockchain exists) – so as long as someone (preferably you) saves a full copy of the blockchain you can still prove the timestamp, or if you use a Merkle Tree root solution (or a multisig transaction) you don’t need to save the blockchain yourself.
* “Blockstamping” is a more suitable name for these services as the exact time in a block is depending on many factors. Also network monitors may receive their clock/date data from other services or computers than the ones used by the entity who found the block. And there is really no exact way to tell what time it is anyway (if you think about it the Bitcoin network itself is a new way of proving that time has passed).