Information security – Access control or authentication – Stand-alone
Reexamination Certificate
2007-02-20
2007-02-20
Barrón, Jr., Gilberto (Department: 2134)
Information security
Access control or authentication
Stand-alone
C726S026000
Reexamination Certificate
active
09851757
ABSTRACT:
The present invention increases the difficulty of interpreting electromagnetic emissions from a keypad system by facilitating randomness in the electromagnetic emissions associated with a particular key activation. A keypad security circuit utilizes a set of digital values that varies over both time and the bits as a keypad driver word applied to a keypad attribute (e.g., a row or column). The keypad security system of the present invention drives the varying strong keypad driver signal to an attribute of a keypad switch matrix (e.g., the rows or columns), applies an independently configured weak driver signals to the opposing attribute of the keypad switch matrix, retrieves a resulting signal from the opposing attribute, and interprets the results to determine if a switch included in a keypad system was activated (e.g., a key is pressed).
REFERENCES:
patent: 4333090 (1982-06-01), Hirsch
patent: 4926173 (1990-05-01), Frielink
patent: 5677687 (1997-10-01), Valdenaire
Buer Mark
Sethia Rajeev
Story Franklyn H.
Barrón Jr. Gilberto
Lipman Jacob
NXP B.V.
Zawilski Peter
LandOfFree
Keypad device security system and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Keypad device security system and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Keypad device security system and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3827443