Abstract: A cryptographic transaction processing system provides read and write interfaces to one or more distributed ledger systems managing respective distributed ledger systems (e.g. blockchains). The system uses the read interfaces to obtain distributed ledger data for respective local data stores that store the data optimized for reading. The data includes confirmed and preferably unconfirmed transactions. Client facing interfaces are provided to client wallets to conduct transactions with respective ledgers. A registration interface is provided to wallets to register public parent keys for respective transaction addresses managed by the wallets for transactions conducted with the ledgers. The registration interface provides read registration identifiers in return.