This Article 
   
 Share 
   
 Bibliographic References 
   
 Add to: 
 
Digg
Furl
Spurl
Blink
Simpy
Google
Del.icio.us
Y!MyWeb
 
 Search 
   
A Class of Randomized Strategies for Low-Cost Comparison of File Copies
April 1991 (vol. 2 no. 2)
pp. 160-170

A class of algorithms that use randomized signatures to compare remotely located filecopies is presented. A simple technique that sends on the order of 4/sup f/log(n) bits,where f is the number of differing pages that are to be diagnosed and n is the number ofpages in the file, is described. A method to improve the bound in the number of bits sent,making them grow with f as flog(f) and with n as log(n)log(log(n)), and a class ofalgorithms in which the number of signatures grows with f as fr/sup f/, where r can bemade to approach 1, are also presented. A comparison of these techniques is discussed.

[1] D. Barbara, H. Garcia-Molina, and B. Feijoo, "Exploiting symmetries for low-cost comparison of file copies," inProc. 8th Int. Conf. Distributed Comput. Syst., June 1988.
[2] H. Chernoff, "A measure of asymptotic efficiency for tests of a hypothesis based on the sum of observations."Ann. Math. Statist., vol. 23, pp. 493-509.
[3] W. K. Fuchs, K. Wu, and J. Abraham, "Low-cost comparison and diagnosis of large remotely located files," inProc. Fifth Symp. Reliability Distributed Software Database Syst., Jan. 1986, pp. 67-73.
[4] T. Madej, private communication.
[5] J. Metzner, "A parity structure for large remotely located replicated data files,"IEEE Trans. Comput., vol. C-32, no. 8, Aug. 1983.
[6] W. W. Peterson,Error-Correcting Codes.Cambridge, MA: MIT Press, 1961.
[7] F. Pittelli and H. Garcia-Molina, "Database processing with triple modular redundancy," inProc. Fifth Symp. Reliability Distributed Software Database Systems, Jan. 1986, pp. 95-103.
[8] F. Pittelli and H. Garcia-Molina, "Recovery in a triple modular redundancy database system," inProc. Seventh Int. Conf. Distributed Comput. Syst., Berlin, Sept. 1987.

Index Terms:
Index Termsrandomized strategies; file copies; randomized signatures; remotely located file copies;differing pages; algorithm theory; file organisation; security of data
Citation:
D. Barbará, R.J. Lipton, "A Class of Randomized Strategies for Low-Cost Comparison of File Copies," IEEE Transactions on Parallel and Distributed Systems, vol. 2, no. 2, pp. 160-170, April 1991, doi:10.1109/71.89062
Usage of this product signifies your acceptance of the Terms of Use.