Embedded Security for Network-Attached Storage,

As storage interconnects evolve from single-host small-scale systems, such as traditional SCSI, to the multi-host Internet-based systems of Network-attached Secure Disks (NASD), protecting the integrity of data transfers between client and storage becomes essential. However, it is also computationally expensive and can impose significant performance penalties on storage systems. This paper explores several tech- niques that can protect the communications integrity of storage requests and data transfers, imposing very little performance penalty and significantly reducing the amount of required cryptography. Central to this work is an alternative cryptographic approach, called "Hash and MAC", that reduces the cost of protecting the integrity of read traffic in storage devices that are unable to generate a message authentication code at full data transfers rates. Hash and MAC does this by precomputing security informa- tion, using and reusing the precomputed information on subsequent read requests. We also present a refined "Hash and MAC" approach that uses incremental hash functions to improve the performance of small read and write operations as well as non-block-aligned operations.