Tl;dr, my Opendime review recommendation: Buy a 3 pack of Opendime’s as a way to carry and trade with “physical” Bitcoin.
Disclaimer: Take everything I am about to say in this Opendime review with a giant grain of salt. I am admittedly a fan boy of the Opendime product, and this product is for sure not for everyone. Opendimes have specific use cases that aren’t needed for buying and hodling Bitcoin, which is what most people care about.
What is an Opendime?
The Opendime website calls it a Bitcoin bearer instrument. It is the only way I know of to securely hand another party physical Bitcoin. Yeah I know, no such thing as physical Bitcoin if you want to get technical about it. However there is the ability to write down your private key, or a passphrase that acts the same, and hand that to somebody effectively giving that person possession / access to the Bitcoin attached to that private key. Opendime does that same thing without revealing the private key to anyone involved in the transaction of the Opendime.
How Does an Opendime Work?
For those that prefer videos:
Opendimes come in packs of three. When you first receive them you can place one inside of a PCs usb-a port. Here it will act similar to a flash drive. There will be some files on it including directions on how to use it.
If you are ready to generate a private key, drag a file into the Opendime folder. Almost any file will work as long as it is not too big. What should happen is the Opendime software will use that file to securely and randomly generate a private key. It will eject itself in software, then restart with new files in it. You will be able to see 1 address that you can deposit too, but you will not be able to see the private key.
If the Opendime does not eject itself in software it will be because the file was not big enough, just drag another file in until it does eject itself.
If the holder of the Opendime decides to extract the funds from the Opendime just push a pin through the hole marked on the back. Insert the Opendime into a PCs usb-a port and you will be able to open the file that contains the now visible private key. Once you have copied the private key you can paste that into a Bitcoin wallet to sweep the funds.
Trust and Opendime
It is important to note here that there are several steps in this process in which you are trusting the company that makes Opendime to not be up to no good when it comes to how the address is generated and whether or not they can see your private key for that address. The Opendime software is all open source, so you can review the software yourself. There is also a way to verify an Opendime’s authenticity by going through a link in the Opendime’s folder, but there is some trust involved if you have not read the open source code.
Again, there is a level of trust here, especially if you are not technically proficient enough to review the Opendime’s source code, so do your own research and be certain you are ready to throw some of your hard earned Satoshi’s on an Opendime beforehand.
What are Opendimes For?
Here are a few use cases for an Opendime:
- Paying another person for a product or service in Bitcoin off-chain
- If you are receiving a payment, an Opendime offers a way to accept Bitcoin funds off-chain and KYC free
- A simple way of storing funds in hardware
- You can “onboard” a friend or family member by giving them physical Bitcoin
In my opinion, transacting in any way with an Opendime requires at least some level of trust between you and the other party. If both parties feel comfortable with the Opendime product, and comfortable verifying funds on the Opendime itself prior to transacting then that would fix the trust involved.
Opendimes are great for having something physical to hand to somebody who is still skittish about Bitcoin. When you have something physical that they can touch and hold, it can be more compelling for some people and could get a newcomer to “go down the Bitcoin rabbit hole.” This is my favorite use case.