Soft updates: a solution to the metadata update problem in file systems
ACM Transactions on Computer Systems (TOCS)
Towards higher disk head utilization: extracting free bandwidth from busy disk drives
OSDI'00 Proceedings of the 4th conference on Symposium on Operating System Design & Implementation - Volume 4
Secure deletion of data from magnetic and solid-state memory
SSYM'96 Proceedings of the 6th conference on USENIX Security Symposium, Focusing on Applications of Cryptography - Volume 6
SSYM'96 Proceedings of the 6th conference on USENIX Security Symposium, Focusing on Applications of Cryptography - Volume 6
A comparison of file system workloads
ATEC '00 Proceedings of the annual conference on USENIX Annual Technical Conference
Hi-index | 0.00 |
Security conscious users of file systems require that deleted information and its associated meta-data are no longer accessible on the underlying physical disk. Existing file system implementations only reset the file system data structures to reflect the removal of data, leaving both the actual data and its associated meta-data on the physical disk. Even when this information has been overwritten, it may remain visible to advanced probing techniques such as magnetic force microscopy or magnetic force scanning tunneling microscopy. Our project addresses this problem by adding support to the Linux kernel for asynchronous secure deletion of file data and meta-data. We provide an implementation for the Ext2 file system; other file systems can be accommodated easily. An asynchronous overwriting process sacrifices immediate security but ultimately provides a far more usable and complete secure deletion facility. We justify our design by arguing that user-level secure deletion tools are inadequate in many respects and that synchronous deletion facilities are too time consuming to be acceptable to users. Further, we contend that encrypting file information, either using manual tools or a encrypted file system, is not a sufficient solution to alleviate the need for secure data deletion.