SETH: A VLSI Chip for the Real-Time Information Dispersal and Retrieval for Security and Fault-Tolerance

In this paper, we describe SETH, a hardwired implementation of the recently proposed \Information Dispersal Algorithm" (IDA) [Rabin:87]. SETH allows the real-time dispersal of information into di erent pieces as well as the retrieval of the original information from the available pieces. SETH accepts a stream of data and a set of \keys" so as to produce the required streams of dispersed data to be stored on (or communicated with) the di erent sinks. The chip might as well accept the streams of data from the di erent sinks along with the necessary controls and keys so as to reconstruct the original information. We begin this paper by introducing the Information Dispersal Algorithm and give an overview of SETH operation. The di erent functions are described and system block diagrams of varying levels of details are presented. Next, we present an implementation of SETH [Bestavros:89] using Scalable CMOS technology that has been fabricated using a MOSIS 3-micon process. We conclude the paper with potential applications and extensions of SETH. In particular, we emphasize the promise of the Information Dispersal Algorithm in the design of I/O subsystems, Redundant Array of Inexpensive Disks (RAID) systems, reliable communication and routing in distributed/parallel systems. SETH demonstrates that using IDA in these applications is feasible.