A minimal blockchain implementation in Elixir inspired by this JS implementation
Blockchain is a distributed database that maintains a continuously-growing list of records called blocks secured from tampering and revision. - Wikipedia
Basically, the 2 main properties of a blockchain are:
- decentralisation: there is no central authority
- immutability: data in the blockchain can't be modified. This is made possible by cryptographic hash functions and proof-of-work
This makes the blockchain a perfect fit to store cryptocurrencies transactions. However, it can also be used to store "any" kind of data. This simple implementation focuses on mechanisms behind a blockchain (see the token app for a cryptocurrency implementation using this blockchain).
- as simple as possible
- peer-to-peer communications
- blockchain logic
- proof-of-work
- in memory
Setup a 3 nodes blockchain as explained in the main readme
You can then add data to the blockchain (from any nodes):
Blockchain.add("some data")Data will be broadcasted on the network so nodes can start to mine it (i.e: compute the proof-of-work). Once a node comes up with the proof-of-work, it adds the block in the blockchain and forwards it to other peers.
This doc explains what is the difficulty and how to determine an appropriate target for your setup. You can then set this target into the :blockchain > Blockchain.ProofOfWork > target config in config.exs.
# connect to a peer (join the blockchain)
Blockchain.connect("host:port")
# list direct peers
Blockchain.peers()
# add data to the blockchain. It will appear once mined
Blockchain.add("some data")
# get all blocks in the chain
Blockchain.blocks()