Staking ledger is a smart contract on the Moonriver parachain that is linked with a nominator account on the Kusama relay chain using the XCM protocol.
Ledgers are isolated subjects that receive xcKSM tokens from Lido and send them to nominators on the relay chain. Ledgers can choose validators for their nominators. If a nominator receives rewards/losses, the ledger will update the stKSM share price according to the changes. All communication between the ledger and the nominator is proceeded via the XCM protocol. All the nominator updates that are introduced on the relay chain are reported to the ledgers by oracles.
Staking ledger exists to control the nominator’s state on the Moonriver parachain.