Proxy Re-encryption(PRE) is greatly concerned by researchers recently. It potentially has many useful applications in network communications and file sharing. Secure distributed cryptographic file system is one of its applications. But the practical applications of PRE are few. And even fewer of them are tested by systematically designed experiments. Appling a couple of representative algorithms proposed by BBS,Ateniese,Shao,et al.,a distributed file system is designed. In the system,some substitute mechani...