Exquisite OpenDime

When we first read about OpenDime, the hardware Bitcoin Wallet, we were exited by what they appeared to have built; a USB Bitcoin device, that is simple to use, tiny, tamper evident and which is free of intimidating bells and whistles. We had to buy some to test, and it lives up to our expectations.

At Azteco, we built a way to deliver Bitcoin that removes all the complexity from the process. You pay for a voucher over the counter, and then redeem its value to any Bitcoin address. You don’t need a wallet of your own. All you need to spend Bitcoin is a piece of paper. It’s the simplest, most direct way to get and spend Bitcoin.

OpenDime have used a similar philosophy; abstract away all the difficulty of using Bitcoin, and reduce the required steps to the absolute minimum, and make a device that anyone can use, without needing to know anything about Bitcoin. They have succeeded.

We ordered a packet of three OpenDimes.

Instant Painless Setup

OpenDime comes in the shape of a mini USB, and setting it up is astonishingly quick and simple. You plug OpenDime into a USB port, and it behaves just like a USB drive with a tiny amount of storage. In its folder, is a web page. You open the webpage in your browser, and there’s only one instruction to follow: “Drop a file onto the drive”. Once you do that, the OpenDime automagically generates a unique address for you to receive Bitcoin with.

You can use that QR Code to send Bitcoin directly to my OpenDime.

Refreshing the page you opened on the drive reveals a new page with a QR code for anyone to send Bitcoin to, and the Bitcoin address for the drive as seen here. You can send Bitcoin to the address, and it immediately shows up on any Blockchain explorer as you would expect. The private key is hidden on the device; not even OpenDime know it.


You now have in your hands, a Bitcoin bearer instrument, that is private and that anyone can verify the condition of by checking its address on a Blockchain explorer and seeing that the tongue is not snapped.

To release the Bitcoin, you break the tongue in the middle of the drive. This reveals the private key and allows the Bitcoin to be spent. The OpenDime can then be discarded. If the tongue in the middle of the drive has not been snapped, you know the Bitcoin is “there” (of course, Bitcoin is not anywhere…but you know this).

Think of the Possibilities

Here’s a scenario where this device could be used. You want to buy a car with Bitcoin. You go to the seller with an OpenDime, and begin negotiations. You try to haggle the price down to the exact amount that is on your device, but the owner won’t budge. He’s a stubborn jerk from New Jersey. You agree to his price and get your wife to add the missing funds to the address of the OpenDime you are carrying. She does this from her phone in Saint Petersburg. You go to the car owner’s computer, plug in the OpenDime. He sees that the Bitcoin is there, you shake hands, give him the OpenDime and the deal is done. He breaks the tongue on the OpenDime, and transfers the Bitcoin to one of his addresses so he can pay bills and do car dealer things. You now own the car.

Here is another scenario…

You're travelling to China to buy scrap metal and other goods worth millions of fiat, and will be paying with Bitcoin. You travel with empty OpenDimes to make all your purchases. Its quick, verifiable and infallible. Customs checks your OpenDimes, and sees that they are not initialized, have no Bitcoin on them, and they wave you through. When you get to your hotel, you initialize all your open dimes, and send the addresses for each one to your accountant back in London.

You get to the warehouse where the scrap metal is being housed, audit it and seal the containers. Your bonded shipping company picks up the containers, and after clearing customs and loading, the price having been agreed upon, the transaction is made at the dock when the goods are on board.

Your office sends the cost of the shipment to your OpenDime. The seller plugs the OpenDime into their laptop, and checks that the Bitcoin has been deposited to the OpenDime’s address on a Blockhain explorer. The deal is completed and there is a permanent, infallible public record of the transfer, that is noted in the contract and related assorted shipping paperwork.

The seller can either break the tongue on the OpenDime and send the Bitcoin to another address, or, he can use it as a bearer instrument with the tongue intact. An Opendime can be passed around an unlimited number of times for any purpose, each recipient of the OpenDime checking its balance against the public Blockchain by simply plugging it in and scanning the Bitcoin address of the device.

How to Think About This.

Unbroken OpenDimes are one way boxes that can accept Bitcoin.
OpenDimes are disposable hardware Bitcoin Wallets.
OpenDimes are Bitcoin Bearer Instruments.

Thinking about this OpenDime future, old OpenDimes could accumulate quite a bit of money as they are passed from one person to another, paying for goods and services. Imagine a story, “The Life and Times of an OpenDime”, a little like The Yellow Rolls Royce. The first use is to buy a bicycle, the tongue is not broken, but instead the device is re-used to recycle the OpenDime. The next purchase is a refrigerator. The buyer tops up the OpenDime before he pays with it. The tongue is not broken. The next purchase is paying six months rent for an office… and the tongue is not broken... and so on and so on, until that same OpenDime is used to buy an apartment in London for £30,000,000. Then it might be broken. Who knows?

An important factor of the above scenario, is that in all the exchanges where the OpenDime device is traded for goods, Bitcoin is never transacted on the Blockchain, only the device changes hands. That means, theoretically, an unlimited number of Bitcoin denominated transactions could take place on OpenDime devices without ever needing to be transmitted, recorded or confirmed. These devices could completely solve the transaction rate “problem”, if everyone used Bitcoin only on a physical OpenDime.

You can come up with your own scenarios of how OpenDime might be used, but no matter the use, what we can say for sure is that what its developers have created is essentially a box that can be filled from anywhere in the world with money.

Obviously, you could build some devices and applications on top of OpenDime. The first one could be an OpenDime Reader. A handheld device that queries Blockchain explorers to check the balance of an inserted OpenDime. Or you could just connect your OpenDime to your iPhone with an adapter and use one of the inevitable OpenDime apps.

There are many ways this device could be used, all of them beneficial to Bitcoin transacting and privacy because OpenDimes are bearer instruments.

OpenDime is just starting, and the people who designed it and wrote its software are clearly gifted. They've done something very difficult; Thinking. They've abstracted away most of the complexity of Bitcoin hardware wallets so that anyone can use them with a minimum of experience, whilst retaining security, increasing privacy and dramatically reducing price. They've also opened up new ways that Bitcoin can be transacted as a physical token of arbitrary size. This is an amazing feat of engineering and insight, and as they work on more features and form factors, you can be certain that an ecosystem of devices and services are bound to accrete around OpenDime.

Normally I don’t write product or service reviews, but in the case of OpenDime, I am doing one not only to heap deserved praise on a brilliant product, but to also make a bigger point about ethics in Bitcoin. OpenDime is a natural part of the “Ethical Bitcoin” movement of developers and entrepreneurs who work with “Bitcoin by its Nature”, creating services and products that serve the customer and which do not violate the customer’s rights. In every factor; usability, utility, price, privacy, ethics, OpenDime is a spectacular achievement, and a superior product, not only in the technical arena but in the important and often overlooked area of ethics. It does everything right.

We sincerely hope that OpenDime succeeds, and dominates. Once they start mass production, the price per unit will drop; even now it is cheaper than any hardware wallet and very much easier to use. OpenDime is an enormous breakthrough. Very exiting stuff!