The First Multisig Physical Bitcoin

The Denarium project started in April when we launched our first two coin products: affordable physical bitcoins with 1/10 & 1/100 in bitcoin value.

Denarium tagline has been “Next Generation Physical Bitcoins” and even though the first series has been a great milestone for us, we believe that it is only now that we are truly starting to deliver on our promise.

This product launch consists of three parts. We are simultaneously launching the 2-of-2 Multisig, our Flagship 1 BTC Series & the innovative Custom Value Coin that is designed to be loaded with a custom bitcoin amount.

Physical Bitcoins with 2-of-2 Multisig

One of the criticisms for our first products was the fact that our coins aren’t trustless. The private key is created by us, therefore the customer needs to trust us. If the plan is to store a large amount of bitcoins in our coins, one doesn’t necessarily want to take any chances. Therefore we wanted to add an option for a trustless Denarium coin.

There are a couple of different methods technically to create a 2-factor coin. We decided to go the route no one has gone before with physical bitcoins (as far as we know) and use multisig.

The way it works is that if the customer wants a multisig coin, he would submit the public key & public address of his/hers Bitcoin address when ordering and then we will create a new Multisig Bitcoin address where the bitcoins will be stored. The bitcoins in that address can only be spent by signing the transaction with both a) the key in the coin and b) the key the customer used when ordering the coin.

We are building an open source tool that allows users to create new private keys and also spend bitcoins easily from a Denarium multisig address. This tool will be launched later this year when we start shipping the new coin products. Instructions on how to generate the keys with some of the popular Bitcoin wallets can be found here.

The Multisig option is available for both our new products, the flagship 1 BTC coin and the Custom Value Denarium. Unfortunately the multisig option isn’t available for the current 1/10 & 1/100 series due to technical incompatabilities.

The Flagship 1 BTC Series

Since we launched the 1/10 & 1/100 series, we have been surprised by the amount of collector interest in our coins. The 1/10 & 1/100 are mainly designed as gift items after all.

We decided to create a coin that complements our line of affordable physical bitcoins in a way that will satisfy the interest of physical bitcoin collectors all over the world.

So, without further ado, here it is.

Concept Art for the 1 BTC Denarium Bitcoin (front)
Concept Art for the 1 BTC Denarium Bitcoin (back)

The 2015 version of the 1 BTC Denarium is a limited edition. The production batch is 250 coins and there will be no more. The coin is .999 fine silver and significantly larger than our brass coins. Diameter of this coin is 40,6mm. The sales are pre-orders and delivery will be in January.

The first 50 coins will be auctioned at Bitcointalk in 3 auctions (20, 15 and 15 coins). Our first auction is now live. The coins are serialized and the serials will be allocated based on the bids. Largest bids get lowest serials. The rest of the batch (200 coins) will be on sale later at Denarium.com with a price based on the auction results. For the sales at our website there will be no special serial number allocations.

Each coin can be bought either as L series (loaded), E series (empty) or M series (multisig). The M series coins can be either loaded with bitcoin value or sent as empty.

Custom Value Coin

Our 2nd new coin product is a no-denomination coin that can be loaded with a custom bitcoin value. We currently allow the coin to be bought with anything from 0,01 to 5 bitcoins pre-loaded. They can also be bought as empty which allows the customer to personally load the coin with any amount of bitcoins.

As we nowadays accept international payment methods such as Visa & MasterCard in addition to Bitcoin, we believe this product has great potential.

Concept Art for the Custom Value Denarium

It is important to note that the actual coins for both the 1 BTC series and the custom value series will likely look slightly different from the concept art. We are going to publish pictures of the actual coins later on.

This coin is the same size as the original 1/10 & 1/100. The first batch is 1000 coins. The coins are serialized but there will be no special serial number allocation. This is a pre-order with delivery scheduled for early December. The product is aimed especially at the Christmas gift market just like our 1/10 & 1/100 series which we still have plenty in stock.

Similarly to the 1 BTC coin, each custom value coin can be bought either as L series (loaded), E series (empty) or M series (multisig). As a reminder to all our US based customers, due to regulation we can only ship the E series or (empty) M series coins to the US.

Finally I would like to mention that we have published a full database of all Denarium coins at GitHub. It is updated daily as new coins are registered & funded. Feel free to play with it.


We are very excited for what year 2016 will bring about for both Bitcoin & Denarium. We are already throwing ideas for our 2016 coin products which will undoubtedly be exciting.

Hopefully you enjoy these products.

PS. If you have any ideas for our future coin products, please contact us.

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