UNDISCOVERABLE PHYSICAL CHIP IDENTIFICATION
First Claim
1. An electronic circuit comprising:
- a first transistor having a first threshold voltage variability;
a second transistor having a second threshold voltage variability;
wherein;
the first transistor comprises a first endpoint node connected to a first voltage and a second endpoint node connected to a second voltage;
the second transistor comprises a first endpoint node connected to the first voltage and a second endpoint node connected to the second voltage;
an enable signal configured and disposed to control a gate of the first transistor and a gate of the second transistor; and
a difference detection circuit disposed between the first endpoint node of the first transistor and the first endpoint node of the second transistor, wherein the difference detection circuit is configured and disposed to generate a signal indicative of a difference in threshold voltage between the first transistor and the second transistor.
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Accused Products
Abstract
Methods and circuits for undiscoverable physical chip identification are disclosed. Embodiments of the present invention provide an intrinsic bit element that comprises two transistors. The two transistors form a pair in which one transistor has a wide variability in threshold voltage and the other transistor has a narrow variability in threshold voltage. The wide variability is achieved by making a transistor with a smaller width and length than the other transistor in the pair. The variation of the threshold voltage of the wide variability transistor means that in the case of copies of intrinsic bit elements being made, some of the “copied” wide variability transistors will have significantly different threshold voltages, causing some of the intrinsic bit elements of a copied chip to read differently than in the original chip from which they were copied.
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Citations
20 Claims
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1. An electronic circuit comprising:
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a first transistor having a first threshold voltage variability; a second transistor having a second threshold voltage variability; wherein; the first transistor comprises a first endpoint node connected to a first voltage and a second endpoint node connected to a second voltage; the second transistor comprises a first endpoint node connected to the first voltage and a second endpoint node connected to the second voltage; an enable signal configured and disposed to control a gate of the first transistor and a gate of the second transistor; and a difference detection circuit disposed between the first endpoint node of the first transistor and the first endpoint node of the second transistor, wherein the difference detection circuit is configured and disposed to generate a signal indicative of a difference in threshold voltage between the first transistor and the second transistor. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An integrated circuit comprising:
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a plurality of intrinsic bit elements, wherein each intrinsic bit element of the plurality of intrinsic bit elements comprises; a first transistor having a first threshold voltage variability; a second transistor having a second threshold voltage variability; wherein; the first transistor comprises a first endpoint node connected to a first voltage and a second endpoint node connected to a second voltage; the second transistor comprises a first endpoint node connected to the first voltage and a second endpoint node connected to the second voltage; an enable signal configured and disposed to control a gate of the first transistor and a gate of the second transistor; and a difference detection circuit disposed between the first endpoint node of the first transistor and the first endpoint node of the second transistor, wherein the difference detection circuit is configured and disposed to generate a signal indicative of a difference in threshold voltage between the first transistor and the second transistor. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A method of generating a unique number within a chip comprising:
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configuring a plurality of intrinsic bit elements within a chip, wherein each intrinsic bit element is configured to generate a bit value; and generating a data value string comprised of data from the plurality of intrinsic bit elements. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification