The Zilliqa blockchain application provides a good example for developers showing how the blockchain conceptual framework is different than specific blockchain implementations. It shows how to adapt the blockchain framework to fit the application.
Scalability has been one of the biggest issues for existing blockchain implementations. Zilliqa’s application offers a high-transaction rate blockchain platform. It can be used in other distributed applications to achieve ultra high transaction rates.
The transaction rate playing field
For reference here’s a rundown of the current transaction rate landscape:
The disparity between traditional payments companies and the Bitcoin and Ethereum blockchain implementations in this chart is staggering. Zilliqa is the first public blockchain implementation that will implement sharding to solve the slow transaction rate problem.
Sharding to up throughput capacity
Sharding will allow for linear scaling as the Zilliqa blockchain grows in size. To shard, in this instance, means to take an entire pool of nodes and dynamically assign each node in such a way as to form sub pools of nodes.
Each sub-pool of servers, or shard, works collaboratively to divide the work and create consensus on validity of transactions.
Blockchain scalability problems result from adding more nodes to a network. The more nodes you have in one large monolithic pool, the harder and slower it is to reach consensus.
Cut down the number of nodes that would have been in the one large pool by assigning to sub-pools, and consensus speeds up dramatically. Additionally, the nodes are compensated more equitably as payment is to all nodes in a shard.
Proof of Work (PoW) is not the answer to scale
Proof of Work is one of the reasons why mining has become such an integral part of some cryptocurrency blockchains. Proof of Work becomes increasingly costly and remains a barrier to scaling transaction rates.
PoW (proof of work) is not the answer. It is only used to defeat sybil attacks and not for consensus. Eliminating PoW as a requirement in a blockchain implementation results in much lower computation requirements.
How Zilliqa scales
Zilliqa has demonstrated 1,750 transactions/second with 4 shards of 2,400 total nodes and expects to be able to deliver 10,000 transaction/second with 10,000 total nodes.
Zilliqa implements a hybrid consensus protocol to grow the network’s throughput with every ~600 new nodes that join. That allows Zilliqa’s throughput to increase by dividing the work, at least on paper.
Zilliqa is also developing and implementing smart contract support that will be compatible with many of the existing smart contract protocols, but not all. To implement smart contracts on the shard architecture requires design and protocol accommodations that some older smart contract designs do not support.
It will be interesting to watch Zilliqa to see what they can achieve and how it might be adopted for real-world applications.