Patent ID: 7743316

Claim:
A computer-implemented method for hiding sensitive data in an electronic spreadsheet, said method comprising: providing a first output equation that expresses an output data as a function of at least one scope input variable whose value intermediate result, at least one model input variable of a model consisting of a cost or pricing model pertaining to the service to be delivered, and at least one first intermediary result, wherein a plurality of first intermediary equations relates the at least one first intermediary result to at least one second intermediary result and one or more model input variables of the model, wherein a plurality of intermediary results denote the at least one first intermediary result and the at least one second intermediary result collectively; assigning the plurality of intermediary results as content of intermediary cells of the spreadsheet; a processor of a computer system generating a second output equation that expresses the output data as a function of the at least one scope input variable, at least one additional scope input variable whose value quantifies an additional scope of the service to be delivered, and a plurality of model input variables of the model, wherein the second output equation has no functional dependence on the plurality of intermediary results, and wherein said generating the second output equation comprises utilizing the first output equation and the plurality of first intermediary equations; in the generated second output equation, said processor replacing each model input variable of the plurality of model input variables by its value to hide each model input variable of the plurality of model input variables by its value and not replacing any scope input variable of the at least one scope input variable and the at least one additional scope input variable by its value, resulting in a third output equation; after said replacing, said processor simplifying the third output equation via a computer algebra engine, resulting in a fourth output equation that expresses the output data as a function of the at least one scope input variable and the at least one additional scope input variable, wherein the fourth output equation has no functional dependence on any model input variable of the model; assigning the output data of the fourth output equation as content of an output cell of the spreadsheet; and after generating the fourth output equation, said processor removing the content of the intermediary cells, resulting in the plurality of intermediary results not being identifiable in the spreadsheet, wherein after said removing has been performed, the fourth output equation cannot be reverse engineered to reveal a dependence of the model on said any model input variable of the model.