BSD Software Development RIPE NCC APNIC JPNIC This document specifies the Erik Synchronization Protocol for use with the Resource Public Key Infrastructure (RPKI). Erik Synchronization can be characterized as a data replication system using Merkle trees, a content-addressable naming scheme, concurrency control using monotonically increasing sequence numbers, and HTTP transport. Relying Parties can combine information retrieved via Erik Synchronization with other RPKI transport protocols. The protocol's design is intended to be efficient, fast, easy to implement, and robust in the face of partitions or faults in the network.