Abstract: A device may include a physically unclonable function (PUF) source that has at least one fuse embedded in the device. The PUF source may be responsive to an input for transmitting a signal through the fuse and providing a PUF value based on a measurement of such signal. The device also has circuitry that is configured to modify the fuse by transmitting a signal of sufficiently high current or voltage through the fuse to change its resistance, thereby changing a response of the PUF source to the input.

Abstract: A transaction device includes a bootloader that a processing unit executes during device startup. The bootloader causes the processing unit to access values from a persistent memory that are relevant to whether a glitch has occurred on a power supply for the processing unit. Based on the values that are acquired from the persistent memory, the processing unit may implement countermeasures, such as disabling certain device operations or delaying the device booting process.

Abstract: A payment terminal has a clock management unit for providing clock signals to components of the payment terminal. The payment terminal also has a wireless communication interface for communicating wireless signals. A processing unit of the payment terminal may monitor clock signals provided by the clock management unit and determine a phase and frequency difference between a clock signal provided to a component producing RF noise and a clock signal provided to a wireless communication interface of the payment terminal. When RF noise present in the received wireless signal falls below a threshold, the processing unit may sample the received wireless signal.

Abstract: A payment terminal has a clock management unit for providing clock signals to components of the payment terminal. The payment terminal also has a wireless communication interface for communicating wireless signals. A processing unit of the payment terminal may monitor clock signals provided by the clock management unit and determine a phase and frequency difference between a clock signal provided to a component producing RF noise and a clock signal provided to a wireless communication interface of the payment terminal. When RF noise present in the received wireless signal falls below a threshold, the processing unit may sample the received wireless signal.

Abstract: A payment terminal has a clock management unit for providing clock signals to components of the payment terminal. The payment terminal also has a wireless communication interface for communicating wireless signals. A processing unit of the payment terminal may monitor clock signals provided by the clock management unit and determine a phase and frequency difference between a clock signal provided to a component producing RF noise and a clock signal provided to a wireless communication interface of the payment terminal. When RF noise present in the received wireless signal falls below a threshold, the processing unit may sample the received wireless signal.

Abstract: A payment terminal has a clock management unit for providing clock signals to components of the payment terminal. The payment terminal also has a wireless communication interface for communicating wireless signals. A processing unit of the payment terminal may monitor operation of a wireless communication interface of the payment terminal and, when the payment terminal is communicating wirelessly, modify an initial clock signal provided to one or more components of the payment terminal that emit RF noise to modify a frequency at which the RF noise occurs. When the payment terminal is no longer transmitting, the processing unit may provide the initial clock signal to the RF noise source.

Abstract: A payment terminal can have an application processing unit coupled to a transaction processing unit. The transaction processing unit can receive payment information from a payment device via a payment interface coupled to the transaction processing unit. The transaction processing unit can encrypt the payment information in accordance with a standard payment protocol and provide the encrypted payment information and other protocol dependent information to the application processing unit. The application processing unit can execute a point-of-sale application that can have the transaction processing unit acquire the payment information and have the application processing unit transmit the encrypted payment information and other protocol-dependent information from the transaction processing unit to a payment server.

Abstract: A communication device has a processing unit, a transmit circuit, and an antenna. The processing unit generates a carrier signal and modifies the carrier signal based on a notch modulation procedure having notch delay and a notch width. The notch width is selected based on a desired modulation index. The resulting modulation signal is provided to the transmit circuit, which generates a wireless data signal that is transmitted by the antenna.

Abstract: A device may include a physically unclonable function (PUF) source that has at least one fuse embedded in the device. The PUF source may be responsive to an input for transmitting a signal through the fuse and providing a PUF value based on a measurement of such signal. The device also has circuitry that is configured to modify the fuse by transmitting a signal of sufficiently high current or voltage through the fuse to change its resistance, thereby changing a response of the PUF source to the input.

Abstract: An electronic device may include a printed circuit board having a physically unclonable function (PUF) source. The electronic device may also include an integrated circuit (IC) chip positioned on the printed circuit board, and the first PUF source may be embedded in or formed on the printed circuit board external to the IC chip. The IC chip has processing circuitry that is configured to determine PUF data based on the PUF source. The processing circuitry is further configured to determine a cryptographic key or authentication token based on the PUF data and to perform at least one secure operation using the cryptographic key or authentication token.

Abstract: A device may include one or more sources such as circuit elements and electrical components that function as sources for physically unclonable function (PUF) data. PUF data may be acquired from the PUF sources and one or more error correction codes may be applied to the PUF data. The resulting PUF values may be used to generate information that may be used for device security operations such as encryption and tamper detection.

Abstract: A device may include one or more sources such as circuit elements and electrical components that function as sources for physically unclonable function (PUF) data. PUF data may be acquired from the PUF sources and one or more error correction codes may be applied to the PUF data. The resulting PUF values may be used to generate information that may be used for device security operations such as encryption and tamper detection.

Abstract: A payment reader includes an anti-tamper circuit for comparing a voltage measured from a temperature sensing circuit with a voltage from one or more threshold nodes. A voltage of a measurement node of the temperature sensing circuit and of each threshold node may correspond to a temperature. A temperature comparison circuit may determine whether a pre-determined temperature threshold has been breached on a comparison of a voltage of the measurement node of the temperature sensing circuit with voltages corresponding to the one or more temperature thresholds. A tamper attempt may be detected if the voltage measured from the temperature sensing circuit exceeds a high voltage threshold or falls below a low voltage threshold. The temperature comparison circuit may provide an output to anti-tamper circuit indicating a result of the comparison.

Abstract: A payment terminal can have an application processing unit coupled to a transaction processing unit. The transaction processing unit can receive payment information from a payment device via a payment interface coupled to the transaction processing unit. The transaction processing unit can encrypt the payment information in accordance with a standard payment protocol and provide the encrypted payment information and other protocol dependent information to the application processing unit. The application processing unit can execute a point-of-sale application that can have the transaction processing unit acquire the payment information and have the application processing unit transmit the encrypted payment information and other protocol-dependent information from the transaction processing unit to a payment server.

Abstract: A device may run an application having information with multiple accounts associated with processing of transactions. The application may provide account information that is used to process the transactions. At the same time, a background application may operate on the device. The background application may be compatible with a second device, and when within range of the second device, may communicate background messages relevant to the transaction. The transaction may then be processed based on the account information and the background messages.

Abstract: A payment terminal can have an application processing unit coupled to a transaction processing unit. The transaction processing unit can receive payment information from a payment device via a payment interface coupled to the transaction processing unit. The transaction processing unit can encrypt the payment information in accordance with a standard payment protocol and provide the encrypted payment information and other protocol dependent information to the application processing unit. The application processing unit can execute a point-of-sale application that can have the transaction processing unit acquire the payment information and have the application processing unit transmit the encrypted payment information and other protocol-dependent information from the transaction processing unit to a payment server.

Abstract: Processor system with a general purpose processor and a cryptographic processor dedicated to performing cryptographic operations and enforcing the security of critical security parameters. The cryptographic processor prevents exposure of critical security parameters outside the cryptographic processor itself, and instead implements a limited scripting engine, which can be used by the general purpose processor to execute operations that require the critical security parameters.

Abstract: A payment processing device can implement a monitoring system to detect for tamper attempts at a physical interface such as a chip card interface. The monitoring system can establish local tamper criteria including a baseline when no chip card is present in the chip card interface, or in some embodiments, when it is known that an authentic chip card is present in the slot. During subsequent evaluations of the chip card interface by the monitoring system, a response received by the monitoring system that deviates from the local test criteria can indicate that a tamper attempt at the chip card interface may have occurred. The payment processing device may also communicate test results to a server for further testing, or for an update of the local test criteria.

Abstract: A payment processing device can implement a monitoring system to detect for tamper attempts at a chip card interface. The monitoring system can establish a baseline when no chip card is present in the chip card interface, or in some embodiments, when it is known that an authentic chip card 14 is present in the slot 21. During subsequent evaluations of the chip card interface by the monitoring system, a response received by the monitoring system that deviates from the baseline can indicate that a tamper attempt at the chip card interface may have occurred. If a tamper attempt is determined by the monitoring system, a remedial or corrective action can be taken.

Abstract: A comparator can incorporate a hysteresis circuit to control when the output of the comparator changes between a high voltage signal and a low voltage signal. The comparator can receive a differential signal and can output either the high voltage signal or the low voltage signal. When the differential input signal is above a first threshold voltage, the output of the comparator can transition to the high voltage signal and when the differential input signal is below a second threshold voltage, the output of the comparator can transition to the low voltage signal. The hysteresis circuit of the comparator is used to adjust the first threshold voltage and the second threshold voltage required to transition the output of the comparator based on the present state of the output signal of the comparator.