The Blockchain as verified public timestamps

Two weeks ago at USV’s annual CEO Summit, Muneeb Ali from OneName explained the blockchain in a way I hadn’t heard before, and which I thought was really helpful: the blockchain is time.

That’s a somewhat abstract way of saying it, so more concretely we could say that:

The blockchain is database of verified public timestamps.

Every bitcoin transaction is kept in a public ledger, and that ledger is verified and maintained by all of the computers participating in the Bitcoin network.  This “chain” of transactions is known as the blockchain, and each transaction is essentially a public timestamp that can contain data.

The key aspects of the blockchain’s timestamps are: decentralized (no one entity controls the database of timestamps, and everyone in the network confirms that timestamp has happened — this is “mining”), immutable (once a timestamp has been verified and recorded, you can’t un-do it), public (all of the timestamps are publicly visible, though some aspects of the data are encrypted), and programmable (you can write code against the blockchain — for example, triggering some sort of action based on the details of a “smart contract” embedded in a timestamp).

Importantly, each of those timestamps contains a packet of data which can hold lots of things: details about a financial transaction, details about a contract between two or more parties, a hashed version of almost any document, etc.

One way I’ve described this is similar to the way people used to use postmarked envelopes to verify that something had happened at a certain time.  For example, signing a will and putting it in an envelope, and mailing it to yourself — the post office’s postmark on the envelope, which has the date of the stamp, proves that whatever was put in the envelope was done so before the date of the stamp.  IIRC, more than once, a mystery on Colombo was resolved using this technique, where a witness dramatically unseals a postmarked envelope before the judge.

The blockchain is essentially a digital, public, programmable version of that.  Which we’ve never had before.

Previously, every app kept its own notion of time. So if I post something on Facebook, Facebook saves that post and timestamps it.  We have to trust them to get that right, and not to change it ever in the future.  This is fine for cat photos, but less fine for a financial transaction, or a deed to a house.

Here’s that same idea in diagram form:

Screen Shot 2015-06-17 at 10.13.03 AM

So in some sense, the Blockchain is a public database — it has the effect of moving data that was previously kept within the walls of one or more apps out into a shared public database.   But to get a little more specific, it’s really a public database of timestamps — a new ability for anyone to state, publicly and immutably, that a certain thing happened at a certain time.

Maybe that is obvious to folks who have been working in this space for a while, but I found it to be a really helpful way of thinking about things — and of explaining it to people who are new to the idea.  Thanks Muneeb!

14 thoughts on “The Blockchain as verified public timestamps

  1. Great explanation @nickgrossman:disqus and @muneeb:disqus. I liked the postmarked envelopes analogy. Different way of explaining it that makes it a bit more clear for what the blockchain can do in a particular point in time. I would still say that it’s a “timestamped database” or “timestamped mini hard drive” works for the layman as well.


  2. I didn’t see Muneeb’s preso, but I would add that it’s a “universal time ledger”.
    Trick is to answer – “so what”, i.e. what can we do with it now? what does it enable? how do we innovate on top?


  3. Exactly! In my “From space to time” presentation I actually have a slide that shows that we’re going from “state based datastores” (databases) to “time based datastores” (blockchain!). The rationale is that state is space: locality determines truth. If record X has a value of K in the the “master” database, then that’s its actual value. In the blockchain, the value of X is not determined by *where* you read it but by the transaction log.


  4. Understandable and a story that normal, smart, tech, business and infrastructure geeks can understand and internalize.

    A criteria that is a big challenge for most everyone who blogs on this topic.

    Thanks for this.


  5. Great post!
    I would clarify that this only works if the blockchain is secure, which for now means proof-of-work, mining and (gasp!) bitcoin. Otherwise the immutability property doesn’t hold.


    1. Yep, that’s right

      If I interpret the “gasp” correctly, it’s because people like me get really excited about the blockchain but are less excited about bitcoin the currency? 🙂


      1. It’s not necessarily about bitcoin as a currency, more that some people think they can get a functioning blockchain without a token of value/scarce commodity. That’s not possible for now, and the only one that exists in the real world is Bitcoin.


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