clarke@csri.toronto.edu (Jim Clarke) (11/19/88)
THEORY SEMINAR - Tuesday, November 29, 3 p.m. in Room GB 221 (GB = Galbraith Building, 35 St. George Street) Michael O. Rabin Professor of Computer Science Harvard University and Professor of Mathematics and Computer Science Hebrew University "Efficient Dispersal of Information for Security Load Balancing and Fault Tolerance" We develop an Information Dispersal Algorithm (IDA) which breaks a file F of length L = |F| into n pieces of Fi, 1 <= i <= n, each of length | Fi| = L/m, so that every m pieces suffice for reconstructing F. Dispersal and reconstruction are computationally effient. The sum of the lengths | Fi| is (n/m)L. Since n/m can be chosen to be close to l, the IDA is space efficient. IDA has numerous applications to secure and reliable storage of information in computer networks and even on single disks, to fault-tolerant and efficient transmission of information in networks, and to communications between processors in parallel computers. For the latter problem we get provably time efficient and highly fault-tolerant routing on the n-cube, using just constant size buffers. -- Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4 (416) 978-4058 BITNET,CSNET: clarke@csri.toronto.edu CDNNET: clarke@csri.toronto.cdn UUCP: {allegra,cornell,decvax,linus,utzoo}!utcsri!clarke