AbstractAlthough several schemes of file sharing for Unixes have been proposed so far, file sharing by these schemes between different administrative domains is difficult and imposes enormous burden on the administrators even if file sharing is possible since the user information differs by such computers in general. In this paper, the file system PNFS (Proxy/Private Network File System), which makes file sharing based on NFS easy between different administrative domains, is proposed. With PNFS, a user can share files of a server that has his account without intervention of its administrator. Although, in general, a decrease in security occurs when intervention of an administrator is omitted, security is enhanced by encryption and the like by the PNFS. In addition, the efficacy of the proposed system has been verified by performance evaluation of a prototype system, which shows a practically sufficient throughput even with simultaneous accesses from a multiple number of clients. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(14): 50–58, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10027