Ardor is a multichain Proof-of-Stake (PoS) blockchain infrastructure that utilises a unique parent-child chain architecture that supports business-optimised smart contracts with an inexpensive transaction fee design. The parent Ardor chain provides security for the network, while the multiple, interoperable child chains provide the rich functionality of the protocol. The main child chain, Ignis, is fully permissionless and provides a number of account-specific functions, such as multi-signature configurations. Ignis also supports several advanced privacy mechanisms such as coin shuffling and encrypted messaging. Ignis is the exclusive chain for development and deployment of Ardor’s stateless lightweight smart contracts. Lightweight smart contracts differ from traditional smart contracts in that they are not executed by every blockchain node, and they provide a layer of automation on top of the Ardor APIs. ARDR is the native token of the Ardor parent chain. The ARDR token is used as the payment method for network functions, as well as staking for the PoS consensus mechanism.