Block, Inc.
Bi-directional communication protocol based device security

Abstract:

A device, such as a payment reader, may include one or more units capable of providing access to sensitive data. Such units may be connected to each other through tamper traces. A secure unit can send known keys or key-value pairs between the units using a multi-directional protocol. The keys or key-value pairs are then compared by the secure unit to monitor or detect a tamper event.