Pufsecurity Corporation

Chun-Heng You

Kai-Hsin Chuang

Chi-Yi Shao

Meng-Yi Wu

A random number generator and a random number generating method are provided. The random number generator includes a first stage generator and a second stage generator. The first stage generator outputs a first random number and a second random number at a first time point and a second time point, respectively. The second stage generator generates a final output at least according to the first random number. More particularly, the second stage generator includes a reseed circuit for generating a reseed signal, to control whether to generate the final output according to the second random number. In addition, when the second stage generator generates the final output at a current data cycle without using the second random number, the first stage generator holds the second random number for generating the final output at a next data cycle.

Random number generator

An anti-tampering detector and a method for detecting a physical attack are provided, wherein the anti-tampering detector includes a temperature sensor, a voltage detector, a frequency detector and a controller. The temperature sensor is configured to generate a temperature code according to an operation temperature. The voltage detector is configured to generate a voltage code according to a supply voltage and the temperature code. The frequency detector is configured to generate a frequency code according to a system clock, the temperature code and the voltage code. The controller is configured to generate an anti-tampering detection result according to the temperature code, the voltage code and the frequency code. The anti-tampering detection result indicates whether any of the operation temperature, the supply voltage and the system clock is tampered with due to the physical attack.

Anti-tampering detector and method for detecting physical attack

A key storage device comprising a first key unit and a second key unit is disclosed. The first key unit is configured to output a first logic value through, comprising: a first setting circuit configured to output a first setting voltage; and a first inverter comprising a first output transistor having a first threshold voltage, configured to receive the first setting voltage and generate the first logic value. The second key unit is configured to output a second logic value through a second node, comprising: a second setting circuit configured to output a second setting voltage; and a second inverter comprising a second output transistor having a second threshold voltage, configured to receive the second setting voltage and generate the second logic value. The absolute value of first threshold voltage is lower than which of the second threshold voltage. The first setting voltage is higher than the second setting voltage.

Key storage device and key generation method

An entropy source circuit is provided. The entropy source circuit includes a digital circuit, a determination circuit and a time-to-digital converter (TDC), wherein the determination circuit is coupled to the digital circuit, and the TDC is coupled to the determination circuit. The digital circuit is configured to generate result data at a second time point according to input data received at a first time point, and the determination circuit is configured to perform determination on reference data with dynamic output generated by the digital circuit, to generate a determination result, wherein the reference data is equal to the result data. In addition, the TDC is configured to perform a time-to-digital conversion on a delay of the digital circuit for generating the result data according to the input data with aid of the determination signal, in order to generate entropy data corresponding to the delay.

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Hsinchu County, Taiwan

Chun-Heng You