Patent application number | Description | Published |
20140181986 | UNIQUE AND UNCLONABLE PLATFORM IDENTIFIERS USING DATA-DEPENDENT CIRCUIT PATH RESPONSES - A method and apparatus are provided for generating a unique identifier. One or more tests are performed over one or more data-dependent circuit paths for one or more circuits. The one or more tests are then repeated over the one or more data-dependent circuit paths for the one or more circuits while adjusting an operating frequency and/or operating voltage for each of the one or more circuits. A threshold frequency and/or threshold voltage is ascertained for each of the one or more data-dependent circuit paths. An identifier may then be generated based on a plurality of the threshold frequencies and/or threshold voltages ascertained for the one or more data-dependent circuit paths. | 06-26-2014 |
20140201851 | METHOD AND APPARATUS FOR USING DYNAMIC VOLTAGE AND FREQUENCY SCALING WITH CIRCUIT-DELAY BASED INTEGRATED CIRCUIT IDENTIFICATION - One feature pertains to a method that includes implementing a Physical Unclonable Function (PUF) circuit, and obtaining a first set of output bits from the PUF circuit by operating the PUF circuit at a first supply voltage level and/or first frequency. Then, at least one of the first supply voltage level is changed to a second supply voltage level and/or the first frequency is changed to a second frequency, where the second supply voltage level and the second frequency are different than the first supply voltage level and the first frequency, respectively. A second set of output bits is then obtained by operating the PUF circuit at the second supply voltage level and/or the second frequency, where the second set of output bits is in part different than the first set. Secure data is generated using the first set of output bits and the second sets of output bits. | 07-17-2014 |
20150058928 | APPLYING CIRCUIT DELAY-BASED PHYSICALLY UNCLONABLE FUNCTIONS (PUFS) FOR MASKING OPERATION OF MEMORY-BASED PUFS TO RESIST INVASIVE AND CLONE ATTACKS - One feature pertains to generating a unique identifier for an electronic device by combining static random access memory (SRAM) PUFs and circuit delay based PUFs (e.g., ring oscillator (RO) PUFs, arbiter PUFs, etc.). The circuit delay based PUFs may be used to conceal either a challenge to, and/or response from, the SRAM PUFs, thereby inhibiting an attacker from being able to clone a memory device's response. | 02-26-2015 |
20150070979 | PHYSICALLY UNCLONABLE FUNCTION BASED ON PROGRAMMING VOLTAGE OF MAGNETORESISTIVE RANDOM-ACCESS MEMORY - One feature pertains to a method of implementing a physically unclonable function. The method includes initializing an array of magnetoresistive random-access memory (MRAM) cells to a first logical state, where each of the MRAM cells have a random transition voltage that is greater than a first voltage and less than a second voltage. The transition voltage represents a voltage level that causes the MRAM cells to transition from the first logical state to a second logical state. The method further includes applying a programming signal voltage to each of the MRAM cells of the array to cause at least a portion of the MRAM cells of the array to randomly change state from the first logical state to the second logical state, where the programming signal voltage is greater than the first voltage and less than the second voltage. | 03-12-2015 |
20150071430 | PHYSICALLY UNCLONABLE FUNCTION BASED ON THE INITIAL LOGICAL STATE OF MAGNETORESISTIVE RANDOM-ACCESS MEMORY - One feature pertains to a method for implementing a physically unclonable function (PUF). The method includes providing an array of magnetoresistive random access memory (MRAM) cells, where the MRAM cells are each configured to represent one of a first logical state and a second logical state. The array of MRAM cells are un-annealed and free from exposure to an external magnetic field oriented in a direction configured to initialize the MRAM cells to a single logical state of the first and second logical states. Consequently, each MRAM cell has a random initial logical state of the first and second logical states. The method further includes sending a challenge to the MRAM cell array that reads logical states of select MRAM cells of the array, and obtaining a response to the challenge from the MRAM cell array that includes the logical states of the selected MRAM cells of the array. | 03-12-2015 |
20150071431 | PHYSICALLY UNCLONABLE FUNCTION BASED ON THE RANDOM LOGICAL STATE OF MAGNETORESISTIVE RANDOM-ACCESS MEMORY - One feature pertains to a method of implementing a physically unclonable function (PUF). The method includes exposing an array of magnetoresistive random access memory (MRAM) cells to an orthogonal external magnetic field. The MRAM cells are each configured to represent one of a first logical state and a second logical state, and the orthogonal external magnetic field is oriented in an orthogonal direction to an easy axis of a free layer of the MRAM cells to place the MRAM cells in a neutral logical state that is not the first logical state or the second logical state. The method further includes removing the orthogonal external magnetic field to place each of the MRAM cells of the array randomly in either the first logical state or the second logical state. | 03-12-2015 |
20150071432 | PHYSICALLY UNCLONABLE FUNCTION BASED ON RESISTIVITY OF MAGNETORESISTIVE RANDOM-ACCESS MEMORY MAGNETIC TUNNEL JUNCTIONS - One feature pertains to least one physically unclonable function based on an array of magnetoresistive random-access memory (MRAM) cells. A challenge to the array of MRAM cells may identify some of the cells to be used for the physically unclonable function. Each MRAM cell may include a plurality of magnetic tunnel junctions (MTJs), where the MTJs may exhibit distinct resistances due to manufacturing or fabrication variations. A response to the challenge may be obtained for each cell by using the resistance(s) of one or both of the MTJs for a cell to obtain a value that serves as the response for that cell. The responses for a plurality of cells may be at least partially mapped to provide a unique identifier for the array. The responses generated from the array of cells may serve as a physically unclonable function that may be used to uniquely identify an electronic device. | 03-12-2015 |
20150074433 | PHYSICALLY UNCLONABLE FUNCTION BASED ON BREAKDOWN VOLTAGE OF METAL- INSULATOR-METAL DEVICE - One feature pertains to a method of implementing a physically unclonable function that includes providing an array of metal-insulator-metal (MIM) devices, where the MIM devices are configured to represent a first resistance state or a second resistance state and a plurality of the MIM devices are initially at the first resistance state. The MIM devices have a random breakdown voltage that is greater than a first voltage and less than a second voltage, where the breakdown voltage represents a voltage that causes the MIM devices to transition from the first resistance state to the second resistance state. The method further includes applying a signal line voltage to the MIM devices to cause a portion of the MIM devices to randomly breakdown and transition from the first resistance state to the second resistance state, the signal line voltage greater than the first voltage and less than the second voltage. | 03-12-2015 |