US5475753 Apparatus and method for certifying the delivery of information
United States Patent US5475753

United States Patent

Patent Number: US5475753

Barbara; Daniel, et. al.

Date of Patent: Dec. 12, 1995


APPARATUS AND METHOD FOR CERTIFYING THE DELIVERY OF INFORMATION

Inventors:

Assignee:

Appl. Number: 93US-151111
Filed: Nov. 12, 1993

Int. Cl.-6

U.S. Cl. Field of Search

References Cited

U.S. PATENT DOCUMENTS

US4653048     3/1987  Anderson et al..............
US4755995     7/1988  Anderson et al..............
US4849978     7/1989  Dishon et al................
US4864569     9/1989  DeLucia et al...............
US4868877     9/1989  Fischer.....................380030000
US4964127    10/1990  Calvignac et al.............
US5005200     4/1991  Fischer.....................380030000
US5019963     5/1991  Alderson et al..............
US5022028     6/1991  Edmonds et al...............
US5029078     7/1991  Iwai........................
US5062045    10/1991  Janis et al.................
US5065400    11/1991  Masuishi et al..............
US5103476     4/1992  Waite et al.................380004000
US5142680     8/1992  Ottman et al................
US5155837    10/1992  Liu et al...................
US5164988    11/1992  Matyas et al................380030000
US5179703     1/1993  Evans.......................
US5204897     4/1993  Wyman.......................380004000
US5204961     4/1993  Barlow......................380006000
US5214702     5/1993  Fischer.....................380050000
US5222134     6/1993  Waite et al.................380004000

OTHER PUBLICATIONS

S. Rangarajan et al., "Rectifying Corrupted Files in Distributed File Systems", Published in Proceedings of the 11th International Conference on Distributed Systems, May 1991.

S. Rangarajan et al., "Optimal Remote File Comparison in Replicated File Systems", Unpublished, Date unknown, Prior to Filing Date of this Application.

Daniel Barbara et al., "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 (Apr. 1991).

Primary Examiner - Cangialosi; Salvatore
Attorney, Agent, or Firm - Ratner & Prestia

ABSTRACT

A method and apparatus by which the recipient of several pieces of newly released information can automatically verify its accurate delivery is disclosed. The first step in the method is to generate a certificate, for example, a checksum, for each of the pieces of information. The certificates are combined, for example, using an exclusive OR function to form elements of a release vector such that each certificate is used to generate multiple ones of the release vector elements. The release vector and a program are then delivered to the recipient by one medium while the pieces of information are delivered by another medium. The program is used at the recipient's location to generate a current vector using the same methods that were used to generate the release vector. Next, the current vector is compared to the release vector and the result is used to identify missing or corrupted pieces of the delivered information.

18 Claims, 3 Drawing Figures

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