An encryption file system that will use similar algorithms as cfs [Blaze93]. For security reasons, all data blocks will be encrypted (both directory and file blocks). Data streams get encrypted before written to the interposed file system (on the way ``down''), and decrypted after being read (on the way ``up'').
An added difficultly in writing this file system, in addition to the problems of stream size changes, will be key management. The file system should enable each individual user to have their own private key for decoding their own files within the encrypted file system.