This paper proposes a cooperative secure reliable storage system depending on pure P2P and supporting self-repair. Participant nodes of this system form an overlay by Paramecium protocol, which maintains the organization of system and provides routing service, or other compatible distributed hash table (DHT) protocols. The PKI authentication mechanism is introduced to ensure security in an open environment. Binding user data with replica identifiers supports secure auto-repair. The introduction of replica types provides secure sharing-write. Preliminary analysis and experiments demonstrate that it maintains a high reliability and read/write performance in real settings while keeping the cost of maintenance bandwidth low.