Pufsecurity Corporation

Chi-Yi Shao

Kai-Hsin Chuang

Meng-Yi Wu

Chun-Heng You

Ching-Sung Yang

Chia-Cho Wu

Jun-Heng You

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 entropy source circuit, comprising: a first adjustable ring oscillator for operating under a first setting or a second setting according to a first control signal, for respectively generating a first oscillation clock signal and a second oscillation clock signal which have different frequencies under the first setting and the second setting; a first sampling circuit, for sampling the first oscillating clock signal according to the sampling frequency to generate first sampling values, or sampling the second oscillating clock signal according to the sampling frequency to generate second sampling values; a first detection circuit detecting a first distribution of the first sampling values; and a control circuit generating the first control signal to switch the first setting to the second setting when the first distribution does not meet a predetermined distribution. The entropy source circuit outputs entropy values according to the first sample value or the second sample value.

Entropy source circuit and entropy value generation method

The present application discloses a method for operating a memory device. The memory device includes a plurality of rows of repair one-time programmable (OTP) cells and a plurality of rows of main OTP cells. The method includes performing a testing procedure to determine validities of the plurality of rows of repair OTP cells and store repair information to a first part of rows of repair OTP cells that are determined to be valid, and performing a repairing procedure to determine validities of the plurality of rows of repair OTP cells and repair at least one row of main OTP cells that is determined to be invalid in the plurality of rows of main OTP by using a second part of the rows of repair OTP cells that are determined to be valid.

Method for operating a memory device and memory device thereof

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

A random number generator includes a static random number generator, a dynamic entropy source, a counter and a combining circuit. The static random number generator includes an initial random number pool and a static random number pool to output a static random number sequence from one thereof the initial random number pool and the static random number pool. The dynamic entropy source is used to generate a dynamic entropy bit. The counter is used to generate a dynamic random number sequence according to the dynamic entropy bit. The combining circuit is used to output a true random number sequence to a lively random number pool according to the static random number sequence and the dynamic random number sequence. The static random number pool is updated when the lively random number pool is fully updated.

Random number generator and method of generating output random number

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.

Entropy source circuit

A built-in self-test (BIST) circuit and a BIST method for Physical Unclonable Function (PUF) quality check are provided. The BIST circuit may include a PUF array, a readout circuit coupled to the PUF array, and a first comparing circuit coupled to the readout circuit. The PUF array may include a plurality of PUF units, wherein each of the PUF units includes a first cell and a second cell. The readout circuit may be configured to output an output bit from the first cell and output a parity bit from the second cell. The first comparing circuit may be configured to compare an output string with a parity string to generate a parity check result, wherein the output string includes output bits respectively read from selected PUF units of the PUF units, and the parity string includes parity bits read from the selected PUF units.

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Hsinchu County, Taiwan

Chi-Yi Shao