173 results about "Verification problem" patented technology

The “identity authentication program” (IAP) creates a custom set of authentication questions in response to a user request to have a user password reset. The IAP accesses a record located in a data source containing information related to the user's recent computer activity and generates an authentication question and a corresponding answer based on the record. In order to reset a user password, the user must correctly answer a designated number of questions from the custom set of authentication questions. In a preferred embodiment, the IAP bases authentication questions on recent e-mail messages sent by the user. Because the questions are generated at the time of the user's request, the answers are unique and can not be memorized. Because the questions are based on recent activities of the user, the questions are hard to guess by an unauthorized person.

The invention provides a multithreaded program output uniqueness detection and evidence generation method based on program constraint building. The output uniqueness verification problem is converted into a constraint solving problem by building a constraint expression according to the multithreaded program semanteme, a constraint solver is used for detecting whether different outputs are present and counter-example execution paths explaining different outputs are generated; the multithreaded program output uniqueness detection and evidence generation method comprises the steps of firstly, carrying out the instrumentation of the detected program, executing the program and obtaining an execution path, secondly, converting the execution path into a quantifier-free first-order logic expression covering all feasible thread interleaving according to the multithreaded program execution semanteme, thirdly, building a uniqueness verification condition aiming at the output result of once operation, and finally, verifying whether one path is present so that the output value is inconsistent with the operation result by use of the constraint solver. The method is capable of detecting whether the output of the multithreaded program is unique under given input; in case of non-uniqueness of the outputs, a counter-example sequence is shown to explain the trigger process of the non-uniqueness.