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US 9,542,576 B1Granted
Magnetic helical physical unclonable function measured above flight
AssigneeLexmark International, Inc.
InventorsAdam Jude Ahne, Graydon Randall Dodson
Life of this patent
Estimating the term…
Abstract
A helical physical unclonable function is disclosed. The helical physical unclonable function may be used to authenticate a supply item for an imaging device. Measurements of the magnetic field above a helical flight are stored in a non-volatile memory to be used by an imaging device to authenticate the supply item. Other systems and methods are disclosed.
Claims20
A supply item for an image forming device comprising:
- a body;
- a physical unclonable function located on the body configured to rotate about an axis of rotation having a shaft centered on the axis of rotation and a helical flight having a length wrapped around the shaft, the helical flight has a top surface furthest away from the axis of rotation, the helical flight contains magnetized particles that generate a magnetic field above the top surface having a varying intensity along the length of the helical flight, the helical flight has a side surface between the shaft and the top surface;
- and
- a non-volatile memory located on the body containing a first array of numbers corresponding to the intensity of the magnetic field radial to the axis of rotation above the top surface along a section of the length of the helical flight at a first plurality of locations each at a first fixed distance from the side surface and also containing a digital signature generated from the first array of numbers.
1 more element
A supply item for an image forming device comprising:
- a body;
- a physical unclonable function located on the body configured to rotate about an axis of rotation having a shaft centered on the axis of rotation, the shaft has a helical channel having a length wrapped around the shaft, the shaft contains magnetized particles that generate a magnetic field above the shaft having a varying intensity, the helical channel has a side surface;
- and
- a non-volatile memory located on the body containing a first array of numbers corresponding to the intensity of the magnetic field radial to the axis of rotation above the shaft along a section of the length of the helical channel at a first plurality of locations each at a first fixed distance from the side surface and also containing a digital signature generated from the first array of numbers.
1 more element
A supply item for an image forming device comprising:
- a body;
- an auger having a spiral flight having magnetized particles that generate a magnetic field above the spiral flight having a varying intensity, the auger is rotatably mounted to the body;
- and
- a non-volatile memory located on the body containing an array of numbers corresponding to the intensity of the magnetic field above a section of the spiral flight and also containing a digital signature generated from the array of numbers.
1 more element
Dependencies are inferred from the claim text.