Abstract: Methods of verifying a genuine presence and identity of a user of a mobile device include analyzing a stream of data from sensors of the mobile device over a period spanning a user press of a button displayed on a touch screen of the device. Results of the analysis are used to distinguish a genuine user button press from a simulated event generated by device emulation software or other simulation tool. The presence and identity verification are determined in part by the results of the sensor stream analysis, optionally in conjunction with an analysis of biometric data captured by the mobile device when the press of a button on the device touch screen has been elicited. The biometric data may include capture of imagery of a user face or body part by a camera of the mobile device.

Abstract: A stack trace associated with an application program is received and at least one recognizable term is searched for in the stack trace. A digital signature is generated from at least a portion of the stack trace that includes the at least one recognizable term. If the digital signature matches a known digital signature among a plurality of known digital signatures, the stack trace is grouped with other stack traces associated with the known digital signature. Method call graphs in grouped stack traces may be analyzed to determine common pathways leading to an error.