Zilliqa is a blockchain platform natively implementing network sharding to massively increase transaction capacity. Emerging in late 2017, the project continues trend of novel blockchain and smart contract platforms seeking to address some of the speed and scaling issues that have dogged the blockchain community in general and developers in particular.
A key challenge for blockchain technology is scaling to meet the needs of an increasing number of participants and applications. Zilliqa is one of the first projects to propose a concrete design to sharding, an innovative blockchain scaling technique which is also a part of the Ethereum development roadmap. Sharding allows blockchain networks to scale by breaking network nodes into subgroups, or shards. Shards work in parallel to process transactions and reach consensus on the blockchain more efficiently. Zilliqa’s operational testnet with limited nodes, or computing power, has processed 2,500 transactions per second across several shards. Zilliqa estimates that with an increased network size of 10,000 nodes, the Zilliqa blockchain will enable a network speed that matches the average transaction rate of VISA and MasterCard with the advantage of much lower fees. Zilliqa will be the first project to implement sharding on a full public blockchain.
Native Sharding: The Sharding concept employed by Zilliqa was first proposed in an academic paper A Secure Sharding Protocol For Open Blockchains (Zilliqa Chief Scientific Officer Prateek Saxena is a co-author). Sharding works by dividing different nodes of a network into subgroups, or shards. Shards then work in parallel to process transactions and reach consensus. Eventually, such transactions are merged into a new block and processed on the blockchain. The main advantages of sharding is that it reduces the amount of data each node needs to store, the number of transactions each node needs to process, and the volume of data that needs to be processed across the network. The Zilliqa team estimates that sharding will allow the Zilliqa blockchain to reach 8,000 to 10,000 transactions per second.
While sharding shows great promise, it has yet to be tested publicly at maximum node capacity and suffers from several challenges that need more research. Sharding introduces some network security issues: attackers may be able to focus attacks on a single shard more effectively, compromising parts of the network. In addition, not as many nodes share as much network information and once a large percentage of the nodes have a problem with the information or lose the information, then no other nodes in the network have that information. Zilliqa hopes to be the forefront of the research on sharding vulnerabilities.
Zilliqa’s Practical Byzantine Fault Tolerance Consensus: Zilliqa’s consensus model is divided into epochs, which last approximately 50 blocks. At the start of the epoch, a set of nodes are elevated to serve on the Directory Services Committee, which is responsible for sharding the network and assigning miners to the shards. During the epoch, each shard generated ‘micro blocks’ and submit those to the DS Committee, which aggregates them into a transaction block and distributes block rewards. At the end of each epoch, one member of the DC committee is swapped out and the entire network is shuffled. This approach relies on a consensus protocol scheme called Practical Byzantine Fault Tolerance (PBFT), which assumes a portion of the nodes in the network will cause errors or be actively malicious. Unlike many proof-of-work and proof-of-stake schemes, in which one validator confirms a bulk of transactions and other validators confirm it, PBFT involves every node independently verifying transactions and then sharing their results with each other. Consensus is reached based on the total decisions submitted by validators. Hyperledger, Stellar, and Ripple all use a variation of PBFT.
Dataflow Paradigm Smart Contract Language: Zilliqa smart contract platform differs from Ethereum’s and leverages its sharded structure to focus on data-intensive computation. In Ethereum’s architecture, contracts are processed sequentially and each node confirms the same computation. In Zilliqa’s sharded architecture, computation can be spread throughout the network and processed simultaneously. To enable this and enjoy the scalability to makes possible, the language will not be Turing-complete. In conversation, the team mentioned it would like to implement formal verification that enables high-level smart contracts. The team also expressed an interest in the potential of moving from a PoW to a Proof-of-Stake mechanism at some point. This focus means that Zilliqa is aiming at highly scalable computations, such as data mining, machine learning, and financial modeling.
Zilliqa conducted a presale contribution round in November of 2017. Zilliqa planned to raise $20 million in total, but due to the significant increase in the ETH/USD exchange rate, the project increased the hard cap to $22 million to allow for Zilliqa community members to contribute after the presale. Community member contributions start on December 27, 2017 and will run for a maximum of 2 weeks. Only members of the Zilliqa Slack channel or Telegram group who joined the respective channels before November 29, 2017 (as well as all waitlisted early contributors) are eligible to participate in the community contribution round. Contributions also exclude United States, United Kingdom, People’s Republic of China, and Japanese citizens. The contribution amount per member is limited to 2.5-5 ETH. Know Your Customer/Anti-Money Laundering (KYC/AML) processes will be enforced and facilitated by Bitcoin Suisse.
After contributions, the Zilliqa public testnet was scheduled to be released in December of 2017. Zilliqa also plans to launch its public main network in Q2 of 2018, with decentralized applications scheduled for delivery the following quarter.
Zilliqa tokens are called, “Zillings,” or ZILs for short. Users will use Zillings to run transactions and smart contracts on the Zilliqa blockchain, similar to how ether functions on Ethereum.
The allocation of tokens from the crowdsale are as follows:
40% of token rewards to miners over 10 years time to incentive miners on the network
30% to tokens to supporters in contribution phases
30% to developer team, advisors, community outreach etc.
The Zilliqa team is exceptionally qualified and reflects a unique academic background. Many on the team are former or current doctoral students and professors at the National University of Singapore’s School of Computing as well as Princeton, Berkeley, and France’s Inria. Zilliqa’s founder is Xinshu Dong, and Chief Scientific Officer is Prateek Saxena. The team has notable advisors including Loi Luu, the founder of the Kyber Network, a decentralized exchange, and one of the original architects of the shading concept. Additionally, Zilliqa has established a team called Zilliqa Research to conduct research and development, and community engagement efforts. Zilliqa’s advisor team is also composed of fintech and banking experts.
While still in the development phase, Zilliqa has announced that it will partner with Mindshare, a digital advertising company based in Singapore. The partnership will involve using the blockchain protocol to improve contextual advertising, develop strategic incentives around data privacy, and create an industry-wide tokenization program used for publisher and content scoring.
|Team openness||Very active and responsive on media channels|
|Blockchain Developer||Prateek Saxena|
|Technical White Paper||Yes|
|Available Project Code||Yes|
|Prototype||Private version has launched with limited node capacity. Version 1 of public testnet scheduled to be released December of 2017|
|Role of token||Access rights|
|Token supply||21 billion tokens|
|Distributed in ICO||12.5 billion|
|Token Price Calculation||The formula to calculate the price is 21,000,000,000 * 30% / (48,889 + Total_Bonus).|
|Blockchain||Proof of Work|
|Consensus method||Practical Byzantine Fault Tolerance|