Bitcoin Forum

I am interested in creating physical coins as I actually currently have a brick and mortar based crypto exchange, I want to sell these locally  however I need to figure out how to create my own, It looks as if all coins created in the past are no longer made but they all seem to have used a shortened private key, was this anything to do on the bitcoin network or simply a 5/6 digit identifier that then associated it's self to the real private key on their website only?

This is what Casascius coins used and I presume others - https://en.bitcoin.it/wiki/Mini_private_key_format

Despite his well earned rep, there's absolutely no way anyone would've bought anything from him if they hadn't had a way of directly accessing the private key. Lots of coin makers have fallen by the wayside so a website based access would be a huge turn off.

Going forward fewer and fewer wallets may support this format. 

I really appreciate the reply, this being said. Does anyone know of wallets currently supporting this format? And would it be a terrible idea to put the whole private key in a circle around the edge of the coin (such as the writing on a US coin) covered by the holograph?

Electrum probably always will, blockchain.info used to, though I'm not sure if they did after it became an HD wallet. I'm sure it's hidden away in a few others too.

If no wallet at all supports it then someone could use this - https://github.com/casascius/Bitcoin-Address-Utility

If you can fit a full private key it would be preferable for future proofing.

Last question I think, is this something I should look into creating myself or do you think these companies would allow us to stock their coins in our shop? It seems most of these companies however are inactive...

Well, I think the physical coin market has taken many a hit from scammers. There've been a few coins that have had all of their balances drained and that may not dispose buyers to trust new ones.

I've often found it rather strange how willing people are to trust complete unknowns with the creation of private keys.

In creating new ones you may also come up against regulations depending on where you are. Casascius shut down as he was threatened with breaching money transmitting regulations.

Perhaps start off on a modest basis and go from there? People do seem to love them regardless. Existing coin creators may well be interested in a physical sales site too, and perhaps coin owners as well. Selling privately online is a bit alarming these days. 

I tried thinking up something that would work as an autonomous unit of currency with various servers
having to sign the coin and ownership during the coins life that would work in a trustless environment
but kept bumping into walls.

in other words the coin itself becomes a software object with it's own life history but clearly I was not
up for the job or I would be mega rich by now.

You said it yourself. It is a terrible idea. Everything physical and tangible can be forged and manipulated by scammers..

It costs $12.5 a piece https://opendime.com/store.

It is an online business, no way any physical can be successful...

There've been plenty of successful physical coins, successful in the sense that they were popular. They certainly don't seem to be a good way to make money for the person actually making them and a whole world of ball ache seems to come along with it.

There was a user here named Gravitate who made the Microsoul coins. He went a bit batty after the constant sniping from users and failures on his part. After doing it for several years I seem to remember him saying his profit was about $5000 in total.

5000 for years of work.. hm, lets think of a better way to make money :)
What about a coin with physical assets behind?

what the point of having one from you would be?
physical assets as in you provide cover for the coin? it won't work
the only way is if you make them similar to caucasian but again the same questions mentioned above will arise
for your coin to be a success you would have to come with an original idea,make it easily shippable and a store of value or a souvenir

You may as well make the coin the physical asset, which is what most coins are anyway.

If I was a coin producer I'd simply hold a decent proportion back and drip feed them onto the market a few years down the line if they were a success.

You would need some sort of "Do It Yourself" private key generation system... so that any private key generated was accessible only by the customer. Otherwise you are going to run into a lot of "trust" issues. :-\

A couple of potential solutions (all with their own benefits/issues):
- Split key generation

• PRO: relatively "safe" for customer, they can be fairly sure you don't have access to the "full" private key
• CON: fairly complicated setup, coin would only be storing "half" the private key, so potential for loss of coins is high

- DIY label kit for customer

• PRO: very "safe" for customer, they can be 100% sure you don't have access to the private key
• CON: a lot of work for customer, could be tricky to print/apply labels correctly etc

- No private key on the coin, only "self funded" public key provided by customer

• PRO: again, very "safe" for customer
• CON: no private key stored with coin, so again, potential for loss is relatively high

I'm sure there are others... I quite like the idea of a physical coin, it is just that the issues associated with keeping private keys "private" seem to be somewhat problematic. :-\