Published on Feb 21, 2020
Zilliqa is a new blockchain platform capable of processing thousands of transactions per second with sharding built into it. With sharding, Zilliqa has the potential to match throughput benchmarks set by traditional payment methods (such as VISA and MasterCard). Even more importantly, Zilliqa’s transaction throughput increases (roughly) linearly with its network size —a feature missing in all popular blockchains.
Existing cryptocurrencies and smart contract platforms are known to have scalability issues, i.e., the number of transactions they are capable of processing per second is limited, usually less than 10. As the number of applications utilizing public cryptocurrencies and smart contract platforms grow, the demand for processing high transaction rates in the order of hundreds and thousands of Tx/s is increasing.
ZILLIQA— a new blockchain platform that is designed to scale in transaction rates. As the number of miners in ZILLIQA increases, its transaction rates are expected to increase. At Ethereum’s present network size of 30,000 miners, ZILLIQA would expect to process about a thousand times the transaction rates of Ethereum. The cornerstone in ZILLIQA’s design is the idea of sharding — dividing the mining network into smaller shards each capable of processing transactions in parallel.
ZILLIQA further proposes an innovative special-purpose smart contract language and execution environment that leverages the underlying architecture to provide a large scale and highly efficient computation platform. The smart contract language in ZILLIQA follows a dataflow programming style which makes it ideal for running large-scale computations that can be easily parallelized. Examples include simple computations such as search, sort and linear algebra computations, to more complex computations such as training neural nets, data mining, financial modeling, scientific computing and in general any MapReduce task
There are two main entities in ZILLIQA: users and miners. A user is an external entity who uses ZILLIQA’s infrastructure to transfer funds or run smart contracts. Miners are the nodes in the network who run ZILLIQA’s consensus protocol and get rewarded for their service. In the rest of this whitepaper, we interchangeably use the terms miner and node. ZILLIQA’s mining network is further divided into several smaller networks referred to as a shard. A miner is assigned to a shard by a set of miners called DS nodes. This set of DS nodes is also referred to as the DS committee. Each shard and the DS committee has a leader. The leaders play an important role in the ZILLIQA’s consensus protocol and for the overall functioning of the network. Each user has a public, private key pair for a digital signature scheme and each miner in the network has an associated IP address and a public key that serves as an identity.
ZILLIQA has an intrinsic token called Zillings or ZILs for short. Zillings give platform usage rights to the users in terms of using it to pay for transaction processing or run smart contracts. Throughout this whitepaper, any reference to amount, value, balance or payment, should be assumed to be counted in ZIL.
We assume that the mining network at any point of time has a fraction of byzantine nodes/identities with a total computational power that is at most f < n 4 of the complete network, where 0 ≤ f < 1 and n is the total size of the network. The factor 1 4 is an arbitrary constant bounded away from 1 3 selected as such to yield reasonable constant parameters. We further assume that honest nodes are reliable during protocol runs, and failed or disconnected nodes are counted in the byzantine fraction .
