Abstract: Methods, apparatus, and systems are disclosed for, among other things, secure passphrase handling for computing devices. In one respect, a method is provided. The method includes receiving a plurality of passphrase elements from an input device. The method also includes performing a sequence of secure delay processing operations, each operation generating a delayed output value from an initial value. The passphrase is verified upon completion of the sequence of secure delay processing operations. Further, initial values of respective secure delay processing operations are based on respective passphrase elements and, for each secure delay processing operation after a first secure delay processing operation, a delayed output value from at least one other secure delay processing operations.

Abstract: Methods, apparatus, and systems are disclosed for, among other things, secure passphrase handling for computing devices. In one respect, a method is provided. The method includes receiving a plurality of passphrase elements from an input device. The method also includes performing a sequence of secure delay processing operations, each operation generating a delayed output value from an initial value. The passphrase is verified upon completion of the sequence of secure delay processing operations. Further, initial values of respective secure delay processing operations are based on respective passphrase elements and, for each secure delay processing operation after a first secure delay processing operation, a delayed output value from at least one other secure delay processing operations.

Abstract: Methods, apparatus, and systems are disclosed for, among other things, providing an electronic record (e.g., MICROSOFT WORD document, AUTOCAD drawing, etc.) that can be signed by “printing” that record to a special “virtual signature printer,” which provides the user with an intuitive, simple way of authenticating an electronic record. The “virtual signature printer” system can produce an output file (or multiple files) that can be sent to a recipient for viewing, printing, and validation. The recipient can view or print the file and, with special software, can validate the signature on the file.

Abstract: Methods, apparatus, and systems are disclosed for, among other things, passphrase input using secure delay, passphrase input with characteristic shape display, user authentication with non-repeated selection of elements with a displayed set of elements, document authentication with embedding of a digital signature stamp within a graphical representation of the electronic document wherein the stamp comprises digits of a digital signature, and sub-hash computation using secure delay.

Abstract: Methods, apparatus, and systems are disclosed for, among other things, passphrase input using secure delay, passphrase input with characteristic shape display, user authentication with non-repeated selection of elements with a displayed set of elements, document authentication with embedding of a digital signature stamp within a graphical representation of the electronic document wherein the stamp comprises digits of a digital signature, and sub-hash computation using secure delay.

Abstract: Methods, apparatus, and systems are disclosed for, among other things, passphrase input using secure delay, passphrase input with characteristic shape display, user authentication with non-repeated selection of elements with a displayed set of elements, document authentication with embedding of a digital signature stamp within a graphical representation of the electronic document wherein the stamp comprises digits of a digital signature, and sub-hash computation using secure delay.