2007 USENIX Annual Technical Conference
Pp. 143–156 of the Proceedings
POTSHARDS: Secure Long-Term Storage Without Encryption
Mark W. Storer, Kevin M. Greenan, and Ethan L. Miller, University of California, Santa Cruz; Kaladhar Voruganti, Network Appliance
Abstract
Users are storing ever-increasing amounts of information digitally, driven by many factors including government regulations and the public’s desire to digitally record their personal histories. Unfortunately, many of the security mechanisms that modern systems rely upon, such as encryption, are poorly suited for storing data for indefinitely long periods of time—it is very difficult to manage keys and update cryptosystems to provide secrecy through encryption over periods of decades. Worse, an adversary who can compromise an archive need only wait for cryptanalysis techniques to catch up to the encryption algorithm used at the time of the compromise in order to obtain “secure” data. To address these concerns, we have developed POTSHARDS, an archival storage system that provides longterm security for data with very long lifetimes without using encryption. Secrecy is achieved by using provably secure secret splitting and spreading the resulting shares across separately-managed archives. Providing availability and data recovery in such a system can be difficult; thus, we use a new technique, approximate pointers, in conjunction with secure distributed RAID techniques to provide availability and reliability across independent archives. To validate our design, we developed a prototype POTSHARDS implementation, which has demonstrated “normal” storage and retrieval of user data using indexes, the recovery of user data using only the pieces a user has stored across the archives and the reconstruction of an entire failed archive.
- View the full text of this paper in HTML and PDF. Listen to the presentation and Q & A in MP3 format.
Until June 2008, you will need your USENIX membership identification in order to access the full papers.
The Proceedings are published as a collective work, © 2007 by the USENIX Association. All Rights Reserved. Rights to individual papers remain with the author or the author's employer. Permission is granted for the noncommercial reproduction of the complete work for educational or research purposes. USENIX acknowledges all trademarks within this paper.
|
