NCryptfs: A Secure and Convenient Cryptographic File System

Often, increased security comes at the expense of user convenience, performance, or compatibility with other systems. The right level of security depends on specific site and user needs, which must be carefully balanced. We have designed and built a new cryptographic file system called NCryptfs with the primary goal of allowing users to tailor the level of security vs. convenience to fit their needs. Some of the features NCryptfs supports include multiple concurrent ciphers and authentication methods, separate per-user name spaces, ad-hoc groups, challenge-response authentication, and transparent process suspension and resumption based on key validity. Our Linux prototype works as a stackable file system and can be used to secure any file system. Performance evaluation of NCryptfs shows a minimal user-visible overhead.