Shielding manipulations of secret data
AssigneeSilverbrook Research Pty Ltd
InventorsKia Silverbrook, Simon Robert Walmsley
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Abstract
This invention concerns a method of shielding manipulations of secret data in an authentication chip from observation. In another aspect it concerns an authentication chip for performing the method. The secret data is manipulated in non-flashing CMOS structures, in which pMOS and nMOS transistors are driven such that they do not have intermediate resistance simultaneously during a change of state of the structure. And at the same time conventional CMOS inverters are operated adjacent the non-flashing CMOS structures.
Claims10
In an authentication chip in which secret data is manipulated, a method of shielding manipulations of the secret data from observation, including the steps of:
- operating non-flashing CMOS structures in the chip, in which pMOS and nMOS transistors are driven such that they do not have intermediate resistance simultaneously during a change of state of the CMOS structure, to manipulate the secret data;
- and
- operating conventional CMOS inverters adjacent the non-flashing CMOS structures at the same time.
An authentication chip, comprising:
- non-flashing CMOS structures, in which pMOS and nMOS transistors are driven such that they do not have intermediate resistance simultaneously during a change of state of the CMOS structure, to manipulate the secret data;
- and
- conventional CMOS inverters adjacent the non-flashing CMOS structures, to change state at the same time the non-flashing CMOS structures manipulate secret data.
Dependencies are inferred from the claim text.