Want to build your own blockchain? It’s easier than it sounds.
Today, we will review how to build a private blockchain using the Komodo platform.
The Komodo platform has it’s own blockchain with a currency named KMD. You can spin-off your own blockchain (asset chain) on the Komodo platform using the Komodo asset chain as a template.
In 2016, Komodo’s Lead Developer, James ‘jl777’ Lee, was working on a project called SuperNET on Nxt, one of the world’s very first blockchain platforms.
The Nxt team implemented major changes to the codebase without consulting any of the projects built on the Nxt platform. The changes broke SuperNET’s backend tech.
This event showed the limitations of the single-blockchain platform model. jl777 issued a Declaration of Independence in response and announced Komodo project. Komodo ICO raised a total of 2,639 BTC in November 2016.
Let analyze blockchain platforms. Bitcoin was the first generation blockchain optimized for security and value store on-chain. Next came Etherum, Waves, and Nxt where any developer could build decentralized apps while sharing a single chain. However, these platforms have problems like scalability and interoperability.
Komodo is a 3rd generation platform, where you can spin off your own blockchain (one like ethereum).
If you’re interested in Etheruem blockchain development, Crowdbotics has a new ERC-20 scaffold that you deploy for free using the Crowdbotics app builder. Give it a try.
Komodo is secure and full of cutting-edge blockchain features. Every chain built using Komodo gets the full features of Komodo blockchain and supports technologies like smart contracts, zero-knowledge privacy, and atomic swap. Komodo prioritizes on 4 key properties.
Komodo uses dPoW as its consensus protocol. Komodo’s dPoW leverages the hashrate of the Bitcoin network for security. Every 10 mints, the komodo blockchain’s snapshot gets saved on Bitcoin blockchain as a backup. This security feature also extends to asset chains being built on Komodo. So, Komodo takes a snapshot of all asset chains and also it’s own state. This snapshot is written into a block on the Bitcoin blockchain. This process is called notarization. There are 64 nodes always running to full fill this purpose.
As per Komodo website:
“The KMD chain serves as a master template from which every other blockchain in our ecosystem is generated. Independent blockchains on Komodo Platform are called assetchains, and each one is a runtime fork of the KMD chain. That means every asssetchain is endowed with zero-knowledge proof privacy features and the protection of dPoW security.”
Asset chains are private chains which have all the features of Komodo chain but they are independent of the other asset chains. The best part is that a single project can run multiple asset chains. They can also sync and talk to each other.
There are many benefits of having your own chain. Let's discuss some of them.
Now, let’s build our own chain called “Dragon” (can’t think of any better name).
Before setting our own asset chain we need to Install Komodo itself, as the Komodo codebase works as a template for our asset chain.
Let’s install komodo. I will be using Google cloud for this purpose. If you have two systems then you can use them. We need to install Komodo in both of them. I am using a Debian system for this. If you are using window or OSX, follow the instructions here and here accordingly.
sudo apt-get update
sudo apt-get install build-essential pkg-config libc6-dev m4 g++-multilib autoconf libtool ncurses-dev unzip git python zlib1g-dev wget bsdmainutils automake libboost-all-dev libssl-dev libprotobuf-dev protobuf-compiler libgtest-dev libqt4-dev libqrencode-dev libdb++-dev ntp ntpdate vim software-properties-common curl libcurl4-gnutls-dev cmake clang
Nanomsg is a socket library that provides several common communication patterns. It aims to make the networking layer fast, scalable, and easy to use. Implemented in C, it works on a wide range of operating systems with no further dependencies.
git clone https://github.com/nanomsg/nanomsg
cmake . -DNN_TESTS=OFF -DNN_ENABLE_DOC=OFF
sudo make install
This takes some time depending on your internet connection. Let it run in the background. Now it is time to install Komodo.
git clone https://github.com/jl777/komodo
git checkout dev
This will take some time. Let’s create a komodo.conf meanwhile. Open a new terminal window and run this.
Add the following lines to the
komodo.conf file (replace
CTRL+X and Y to save and exit nano editor.
Now you can start
komodod daemon to sync with the network. This will take time.
./src/komodod -addnode=22.214.171.124 -daemon
You will see some outputs in the terminal where you started the
komodod daemon. You can check logs using below
tail -f debug.log
Now as we installed komodo daemon
komodod, we can now use
komodo-cli to run commands. For example, run this:
You will see output like this.
In this output when you see
longestchain values become the same, it means, your wallet is full synced.
you should protect your wallet (wallet.dat) which resides in
~/.komodo/wallet.dat Make several copies of this file and protect them.
Now, follow the same instructions in the 2nd machine. We are then ready to spin up our own asset chain after that.
Komodo is a fork of Zcash which in turn is a fork of Bitcoin. So, Komodo uses a lot of bitcoin codebase. It needs to nodes (Systems) to run set a blockchain. The reason for 2 nodes (systems) is that the original blockchain designs of Satoshi Nakamoto, on which Komodo is based, donot exist on a single node. Rather, it exists via a connection between two or more nodes. This is the nature of decentralization: it is on the network we rely, rather than a single authority.
Before going forward we need to check that we are able to ping both machines from one another.
Let’s spin up our Dragon chain on node 1. Before then, we will stop Komodo daemon using below commands.
Let’s create our own asset chain using below command on node1.
./komodod -ac_name=DRAGONCHAIN -ac_supply=1000000 -addnode=<IP address of the second node> &
You can use more available parameters to get more configuration. After running this command you get output something like this.
>>>>>>>>>> DRAGONCHAIN: p2p.8096 rpc.8097 magic.c89a5b16 3365559062 1000000 coins
In this case, the p2p port is
8096. You need to make sure that this port will be open on machines.
Setup 2nd node
Now on the second node, stop the Komodo daemon and run the command below. We need to give it the IP address of the first node . We are giving a few extra parameters here -gen -genproclimit=1 to start mining as soon as it connects to 1st node.
./komodod -ac_name=DRAGONCHAIN -ac_supply=1000000 -addnode=<IP address of the first node> -gen -genproclimit=1 &
Once the second node connects it will automatically mines blocks.
On a Komodo-based blockchain, all of the pre-mined coins are mined in the first block. Therefore, whichever machine executes the mining command will receive the entirety of the blockchain supply.
You can sell these coins to your customers, using either our native DEX, BarterDEX or a third party exchange.
To get the information about the asset chain you run this command.
./komodo-cli -ac_name=DRAGONCHAIN getwalletinfo
To get the balance,
./komodo-cli -ac_name=DRAGONCHAIN getbalance
or to know about more APIs and RPC calls you can run this command.
./komodo-cli -ac_name=DRAGONCHAIN help
Now you have your asset chain and DragonChain tokens the you can list it on exchanges. (Of course you need to come with the application and sell it to customers first). BarterDex is one of the decentralize exchanges built by the Komodo team. You can list ERC20 and other bitcoin base cryptocurrencies on this exchange.
Komodo introduced it’s own UTXO (Unspent transaction outputs) based smart contracts called Cryptoconditions. These contract are different from ethereum or Eos Turing complete smart contracts which runs on a virtual machine and uses GAS model. Cryptoconditions do not take gas for their execution.
As Komodo is a bitcoin-protocol based platform, it uses UTXO model as compared to Ethereum’s address base model. So, Cryptocondition contracts works on UTXO rather than lock the balance of whole address. To understand this better, you can think UTXOs as bills on your wallet. Let’s say you have a bill of 2$, 5$ and 10$ in your wallet. Using Cryptocondition you can lock on a particular bill (fox example — 5$ bill) and other bills will be untouched. This makes UTXOs programmable.
Benefits of Cryptocondition over Ethereum smart contracts
In the world of Decentralized apps, asset chains can enable a lot of use cases and technologies such as atomic swap, which helps in interoperability of blockchains and value transfer between multiple chains.
Komodo is building a blockchain platform with leading edge technology and hopes to power a whole new generation blockchain applications. The ecosystem needs to grow as compared to ethereum and other blockchains, but build something valuable always takes time.
Any business or individual with long-term blockchain application use cases should look into Komodo’s asset chain platform.
If you have any problems checkout the official documentation of Komodo platform or leave a question on this post. If you’ve built on the Komodo platform, drop a link to your project in the comments. I’d love to check it out.
Thanks to William Wickey for help editing.
December 5, 2018