Educational Testing Service

Ker-Ming Chang

Dennis C Quardt

Edwin O Blew

A method and system for encryption and decryption of data files on a web-based computer system includes encrypting the data file in a memory subsystem, such as RAM, storing the encrypted data file in one or more of a plurality of memory locations, analyzing and modifying the encrypted data file, retrieving and decrypting the modified data file, and displaying the decrypted data file on a web browser. The computer system may include one to three servers. The data file may be encrypted and decrypted using any dual-key encryption algorithm, such as PGP, or a single key algorithm. Data transmitted into and out of the computer system may be via an SSL/HTTPS protocol to provide additional security.

Methods for conducting server-side encryption/decryption-on-demand

A method for the optimization of optical scanners by automatically determining image processing threshold values using a novel threshold calibration sheet. The calibration sheet image has lines at a forty-five degree angle to the path of the document through the scanner and has a predetermined image dot count. One embodiment comprises the steps of repetitively scanning the sheet until scanner threshold values which satisfy predetermined relationships with said dot count are determined. Another embodiment comprises the steps of a single calibration scan with multiple processing of the gray scale scan data on a host computer. By using this method, two or more scanner cameras can work together on processing document images and consistently give uniform results, independent of their individual technical operating or performance differences.

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Princeton, NJ, United States of America

Ker-Ming Chang