Square, Inc.

Block, Inc.

Securekey Technologies Inc.

Sqaure, Inc.

Yue Yang

Afshin Rezayee

Jeremy Wade

Malcolm Smith

Max Joseph Guise

Kamran Sharifi

Ravi Shivnaraine

Alain Rousson

Kajornsak Julavittayanukool

Bertram Leesti

Jesse Wilson

Kevin Ng

Kevin Ka Wai Ng

William Hardy

Emad Bidari

Jason Binder

Haipeng Yan

A transaction 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 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 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.

Line-based chip card tamper detection

An electronic device may include a printed circuit board having a physically unclonable function (PUF) source. The electronic device may also include processing circuitry positioned on the printed circuit board. The PUF source includes a plurality of traces and each trace includes a first portion and a second portion having an increased surface area relative to the first portion. The PUF source is responsive to an input from the processing circuitry to provide PUF data based on the impedance characteristics of the plurality of traces. The processing circuitry is further configured to process the PUF data from the PUF source to perform an operation within the device.

Device security with physically unclonable functions

An electronic device, such as a payment reader, may include a physically unclonable function (PUF) source to generate a plurality of PUF values. The electronic device may also include circuitry to compare the plurality of PUF values from the PUF source to determine a degree of randomness of the at least one PUF source in generating the plurality of PUF values. The circuitry can then determine, based on the determined degree of randomness, whether to use the PUF values from the PUF source to perform a secure operation for the electronic device.

A transaction chip can exchange information with a chip card during a payment transaction. The transaction chip can incorporate a processing unit, a memory device, a contact interface and power and communication circuitry. The transaction chip can acquire payment information from the chip card when the EMV chip of the chip card is interfaced with the power and communication circuitry of the transaction chip via the contact interface. The transaction chip can also process the acquired payment information and transmit the processed payment information to a point-of-sale application of a merchant device via a wireless

Transaction chip incorporating a contact interface

An electronic device may include circuitry and an anti-tamper device having a physical characteristic that changes in response to a tamper attempt. The circuitry is configured to determine physically unclonable function (PUF) data based on the physical characteristic and to perform at least one secure operation based on the PUF data. The circuitry is further configured to detect the tamper attempt based a change to the physical characteristic and to perform at least one action in response to detection of the tamper attempt for protecting the electronic device from the tamper attempt.

Devices with on-board physically unclonable functions

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.

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 cardis 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 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.

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.

A transaction device includes circuitry that provides a power supply to a processor of the transaction device. Attackers may attempt to glitch the processor power supply in a manner that causes processor to operate incorrectly such as by skipping instructions. A monitoring circuit may be coupled to the processor power supply circuitry to identify conditions that are indicative of a glitch attempt. Glitch attempts may be stored in a memory and reported to the processor to induce the execution of counter-measures.

Processor power supply glitch detection

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.

Server-enabled chip card interface tamper detection

A payment reader includes a tuning circuit that provides a tuned transmission source signal to an antenna for transmission. A sense circuit coupled to the antenna provides a measured transmitted signal to a binary phase detection circuit. The binary phase detection circuit filters and processes the signal to provide an analog phase signal that corresponds to a phase difference between the measured transmitted signal and the transmission source signal. A comparison circuit compares the analog phase signal to a reference signal, and a decision circuit adjusts the operation of the transmission circuitry based on the comparison.

Transmit phase detection circuit

An expedited booting process with brownout detection for a payment reader is provided. The payment reader can execute a boot sequence from read only memory at startup. A check is made of a stored flag value to determine whether a value such as a flag indicates whether or not a prior execution of the boot sequence was successful. If the last execution of the boot sequence was successful, the boot sequence can be executed at a faster clock rate. Otherwise the boot sequence is executed at a slower clock rate. An evaluation can be made to determine whether a predetermined portion of the boot sequence has been surpassed. If the predetermined portion of the boot sequence has been surpassed, the flag value can be set to indicate a successful execution of the boot sequence and the general operating instructions for the payment reader are then executed.

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Thornhill, Canada

Yue Yang