Title :
Accountable Web-computing
Author_Institution :
Dept. of Comput. Sci., Massachusetts Univ., Amherst, MA, USA
Abstract :
We develop a computationally lightweight scheme. for enhancing security when sharing a massive "bag of tasks" on the Web, by enabling the tasks owner to keep track of which "volunteer" computed which tasks. The scheme combines a directory that dynamically assigns names to volunteers, who can arrive and depart at will, with a directly computed task allocation function (TAF) that assigns tasks to each volunteer-name from a reserved "sub-bag." We design a methodology for constructing easily computed additive TAFs (ATAFs), which assign each volunteer-name υ a base task Bυ and a stride Sυ and then index every sub-bag by an arithmetic progression: Bυ, Bυ+Sυ, Bυ+2Sυ, .... The scheme ensures that faster volunteers are always assigned smaller strides, thereby simplifying the management of the memory where tasks reside. We seek to simplify memory management further by striving for ATAFs whose strides Sυ grow slowly as a function of υ. We present a sequence of ATAFs whose strides grow progressively slower; with only modest concomitant increase in computational complexity: The sequence ranges from easily computed ATAFs whose strides grow exponential v, to slightly more complex ATAFs whose strides grow quadratically to somewhat complex ATAFs whose strides grow subquadratically.
Keywords :
Internet; computational complexity; information resources; resource allocation; accountable web computing; arithmetic progression; computational complexity; computationally lightweight scheme; security; task allocation function; Arithmetic; Computational efficiency; Computer science; Computer security; Concurrent computing; Design methodology; Distributed computing; Memory management; Parallel processing; Registers;
Conference_Titel :
Parallel and Distributed Processing Symposium., Proceedings International, IPDPS 2002, Abstracts and CD-ROM
Conference_Location :
Ft. Lauderdale, FL
Print_ISBN :
0-7695-1573-8
DOI :
10.1109/IPDPS.2002.1015578