Kadena offers a private blockchain solution designed to scale to thousands of users and a public system of parallel blockchains called Chainweb. Kadena have also designed a user-friendly smart contract programming language called Pact, which emphasizes formal verification and supports modular updates to the smart contracts across the network without the need for hard-forks. Chainweb is designed to support transaction throughput significantly greater than that of existing PoW blockchains. This is achieved via a system comprising multiple blockchains referencing one another where the resulting ‘super chain’ is designed to achieve transaction throughput of the order of 10,000 per second. Founder William Martino has experience as lead engineer on a projects for JP Morgan’s Emerging technology group, where he researched consensus mechanisms via a fork of Tangaroa a consensus mechanism written in Haskell. He also held the post of Senior Science Advisor to the SEC.
Kadena is designed to be a scalable blockchain solution that yet continues to employ PoW consensus, which the team believe afford them advantages from a regulatory perspective not afforded other consensus mechanisms more typically considered to aid in scaling. Unlike many PoS consensus mechanisms, PoW is exempt from U.S. Money-Transmitter (MTA) regulation in virtue of the probabilistic nature of block production and distribution of the associated rewards. Parallel PoW can draw from hundreds or thousands of chains to create one large network, achieving large throughput and enjoying enhanced security guarantees as a result of the inter-referencing of the blocks between chains. Kadena’s smart contracts include Simple Payment Verification (SPV) technology inspired by Bitcoin for multiple blockchains, whereby a transaction can verified via a light client rather than a copy of the entire blockchain, enabling trustless transfer of assets across different chains. Kadena limits congestion fees, such as those seen associated to BTC transactions during times of high network activity, by facilitating a higher transactional throughput for the same amount of hashing resources. The Pact programming language is Turing incomplete, so looping programs are only able to execute over finite lists of operations, preventing infinite loops of computation from perturbing the network. Kadena's public blockchain launched January 2020.
Kadena's token, KDA, is rewarded to miners who discover valid bocks, incentivizing miners to contributed to network security. KDA is also used to pay for smart contract creation, executions, and direct transfers, broadly functioning the same way as Ethereum's gas. At genesis, block rewards were 2.3 KDA per block with a 30-second target block time. Mining rewards are programmed to decrease approximately 0.3% every 87,600 blocks, eventually dropping to zero at block height 125,538,057.