Decentralized Access Control in Networked File Systems

The Internet enables global sharing of data across organizational boundaries. Traditional access control mechanisms are intended for one or a small number of machines under common administrative control, and rely on maintaining a centralized database of user identities. They fail to scale to a large user base distributed across multiple organizations. This survey provides a taxonomy of decentralized access control mechanisms intended for large scale, in both administrative domains and users. We identify essential properties of such access control mechanisms. We analyze popular networked file systems in the context of our taxonomy

Decentralized Access Control in Distributed File Systems

The Internet enables global sharing of data across organizational boundaries. Distributed file systems facilitate data sharing in the form of remote file access. However, traditional access control mechanisms used in distributed file systems are intended for machines under common administrative control, and rely on maintaining a centralized database of user identities. They fail to scale to a large user base distributed across multiple organizations. We provide a survey of decentralized access control mechanisms in distributed file systems intended for large scale, in both administrative domains and users. We identify essential properties of such access control mechanisms. We analyze both popular production and experimental distributed file systems in the context of our survey

Secure and Flexible Global File Sharing

Sharing of files is a major application of computer networks, with examples ranging from LAN-based network file systems to wide-area applications such as use of version control systems in distributed software development. Identification, authentication and access control are much more challenging in this complex large-scale distributed environment. In this paper, we introduce the Distributed Credential Filesystem (DisCFS). Under DisCFS, credentials are used to identify both the files stored in the file system and the users that are permitted to access them, as well as the circumstances under which such access is allowed. As with traditional capabilities, users can delegate access rights (and thus share information) simply by issuing new credentials. Credentials allow files to be accessed by remote users that are not known a priori to the server. Our design achieves an elegant separation of policy and mechanism which is mirrored in the implementation. Our prototype implementation of DisCFS runs under OpenBSD 2.8, using a modified user-level NFS server. Our measurements suggest that flexible and secure file sharing can be made scalable at a surprisingly low performance cost

A Study of the Relative Costs of Network Security Protocols

While the benefits of using IPsec to solve a significant number of network security problems are well known and its adoption is gaining ground, very little is known about the communication overhead that it introduces. Quantifying this overhead will make users aware of the price of the added security, and will assist them in making well-informed IPsec deployment decisions. In this paper, we investigate the performance of IPsec using micro- and macro-benchmarks. Our tests explore how the various modes of operation and encryption algorithms affect its performance and the benefits of using cryptographic hardware to accelerate IPsec processing. Finally, we compare against other secure data transfer mechanisms, such as SSL, scp(1), and sftp(1)

Safety and Performance in an Open Packet Monitoring Architecture

Packet monitoring arguably needs the flexibility of open architectures and active networking. A significant challenge in the design of open packet monitoring systems is how to effectively strike a balance between flexibility, safety and performance. In this paper we investigate the performance of FLAME, a system that emphasizes flexibility by allowing applications to execute arbitrary code for each packet received. Our system attempts to achieve high performance without sacrificing safety by combining the use of a type-safe language, lightweight run-time checks, and fine-grained policy restrictions. Experiments with our prototype implementation demonstrate the ability of our system to support representative application workloads on Bgit/s links. Such performance indicates the overall efficiency of our approach; more narrowly targeted experiments demonstrate that the overhead required to provide safety is acceptable

A Study of the Relative Costs of Network Security Protocols

While the benefits of using IPsec to solve a significant number of network security problems are well known and its adoption is gaining ground, very little is known about the communication overhead that it introduces. Quantifying this overhead will make users aware of the price of the added security, and will assist them in making well-informed IPsec deployment decisions. In this paper, we investigate the performance of IPsec using micro- and macro-benchmarks. Our tests explore how the various modes of operation and encryption algorithms affect its performance and the benefits of using cryptographic hardware to accelerate IPsec processing. Finally, we compare against other secure data transfer mechanisms, such as SSL, scp(1), and sftp(1)

Secure and Flexible Global File Sharing

Trust management credentials directly authorize actions, rather than divide the authorization task into authentication and access control. Unlike traditional credentials, which bind keys to principals, trust management credentials bind keys to the authorization to perform certain tasks