A method for utilizing a plurality of physical unclonable function (PUF) cells to generate a signature key with a desired bit length is provided. The method includes setting a state of each of the plurality of PUF cells to a uniform level; obtaining an order of change in the state of at least a portion of the plurality of PUF cells; and generating the signature key at least based on the order.

There is provided a method for testing a Physically Unclonable Function (PUF) implemented in a device, said PUF being configured to receive at least one challenge, each challenge comprising a set of bits, and to produce a set of responses, each response comprising at least one bit and corresponding to one challenge, said PUF comprising a circuitry including a set of PUF elements, each PUF element being controlled by at least one input bit corresponding to at least one bit of said challenge, wherein the method comprises the steps of: applying at least one bit of the challenge to the PUF instance; determining (300) identifiers for at least some of the PUF elements, the identifier of each PUF element being determined from the response output by said PUF element in response to said at least one bit of the challenge; applying a statistical randomness test (304) to a group of identifiers comprising at least some of the identifiers determined for said PUF elements, which provides a test indicator; and testing said PUF based on said test indicator.

The invention relates to the field of computer engineering and cryptography and, in particular, to methods for implementing linear transformations which operate with a specified speed and require minimum amount of memory, for further usage in devices for cryptographic protection of data.

The technical result relates to enabling to select inter-related parameters (performance and required amount of memory) for a particular computing system when implementing a high-dimensional linear transformation.

The use of the present method allows to reduce the amount of consumed memory at a given word size of processors employed.

To this end, based on a specified linear transformation, a modified linear shift register of Galois-type or Fibonacci-type is generated according to the rules provided in the disclosed method, and the usage thereof enables to obtain the indicated technical result.

A system and method use a physical unclonable function in a PUF circuit on an integrated circuit to generate a security key, and stabilize the security key by storage in a set of nonvolatile memory cells. The stabilized security key is moved from the set of nonvolatile memory cells to a cache memory, and utilized as stored in the cache memory in a security protocol. Also, data transfer from the PUF circuit to the set of nonvolatile memory cells can be disabled after using the PUF circuit to produce the security key, at a safe time, such as after the security key has been moved from the set of nonvolatile memory cells to the cache memory.

A processing system includes a memory and a cryptographic accelerator operatively coupled to the memory. The cryptographic accelerator performs a split substitute byte operation within two paths of a cryptographic round by determining a first output from a first path by applying a mapped affine transformation to an input bit sequence represented by an element of a composite field of a finite-prime field, wherein the first output is represented by a first element of the composite field of the finite-prime field, and a second output from a second path by applying a scaled mapped affine transformation to the input bit sequence, wherein the second output is represented by a second element of the composite field and is equal to a multiple of the first output in the composite field.

Terminal devices that perform machine-to-machine (M2M) communication may autonomously perform password authentication by autonomously generating a personal identity number (PIN) value, which is not exposed externally, using a physical unclonable function (PUF). A terminal apparatus that performs M2M communication may include a PUF embedded in the terminal apparatus to generate an authentication key for password authentication associated with the terminal apparatus, and an authentication unit to perform the password authentication associated with the terminal apparatus using the authentication key generated by the PUF.

Methods and systems are directed to creating a physical unclonable function (PUF) on a Field Programmable Gate Array (FPGA) and generating a unique signature for a device. The method includes, in part, designing a PUF by taking advantages of programmable logic elements on the FPGA, and extracting uninitialized values associated with one or more storage elements comprised in the PUF when the FPGA is powered up. The extracted uninitialized values can be combined to generate the unique signature for the device. The one or more storage elements can be bi-stable memory cells that are mapped to look up tables (LUTs) on the FPGA. The coordinates of these LUTs can be determined based on hamming distance analysis. Alternatively, the one or more storage elements can be memory cells associated with boundary scan cells of a boundary scan chain.

An embodiment includes an apparatus comprising: an out-of-band cryptoprocessor coupled to secure non-volatile storage; and at least one storage medium having firmware instructions stored thereon for causing, during runtime and after an operating system for the apparatus has booted, the cryptoprocessor to (a) store a key within the secure non-volatile storage, (b) sign an object with the key, while the key is within the cryptoprocessor, to produce a signature, and (c) verify the signature. Other embodiments are described herein.

A technique is presented for performing a physical unclonable function (PUF) using an array of SRAM cells. The technique can be viewed as an attempt to read multiple cells in a column at the same time, creating contention that is resolved according to process variation. An authentication challenge is issued to the array of SRAM cells by activating two or more wordlines concurrently. The response is simply the value that the SRAM produces from a read operation when the challenge condition is applied. The number of challenges that can be applied the array of SRAM cells grows exponentially with the number of SRAM rows and these challenges can be applied at any time without power cycling.

The physically unclonable function device (DIS) comprises a set of MOS transistors (TR1i, TR2j) mounted in diodes having a random distribution of respective threshold voltages, and comprising N first transistors and at least one second transistor. At least one output node of the function is capable of delivering a signal, the level of which depends on the comparison between a current obtained using a current circulating in the at least one second transistor and a current obtained using a reference current that is equal or substantially equal to the average of the currents circulating in the N first transistors. A first means (FM1i) is configured to impose on each first transistor a respective fixed gate voltage regardless of the value of the current circulating in the first transistor, and a second means (SM2j) is configured to impose a respective fixed gate voltage on each second transistor regardless of the value of the current circulating in the second transistor.