Tamper-Resistant EPP Using Quantum Tunneling Composite
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Solution Overview
Problem
Conventional Encrypting PIN pads (EPPs) are vulnerable to front side attacks, which can bypass tamper detection mechanisms and compromise the security of PIN codes and cryptographic keys, posing a risk to both customers and financial institutions.
Innovation Solution
The EPP incorporates a composite layer with Quantum Tunnelling Composite (QTC) material and elastomeric binder, along with an actuator member and electrode elements, to create an electrically conductive bridge that changes resistance when tampered with, triggering an alarm or self-destruct function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional separation switches are used to detect tampering, then the EPP can detect when the keypad becomes separated from the body, but the switches can be bypassed by injecting electrically conductive ink or adhesive to maintain contact
Solution Approach 1:
The patent introduces an intermediary conductive layer with distributed conductive particles between the keypad and main body. This intermediary structure makes it extremely difficult for attackers to bypass the tamper detection, as they would need to disrupt the distributed particle network throughout the entire contact surface rather than simply gluing down a single switch.
Solution Approach 2:
The patent changes the physical state and electrical properties of the contact interface by using a layer whose electrical conductivity varies based on pressure and separation. When the keypad is properly attached, the conductive particles form continuous pathways; when separated, the conductivity changes detectably, providing reliable tamper detection.
2Reliability
If probing detection circuits are used to detect front side attacks, then the EPP can output a self-destruct signal, but the circuits can be bypassed or damaged to gain access to the main control board
Solution Approach 1:
The patent merges the tamper detection functionality directly into the structural contact layer between the keypad and main body. By combining the structural integrity function with the electrical detection function in a single integrated layer, the system achieves robust protection without adding separate complex detection circuits that could be bypassed or damaged.
3Ease of operation
If multiple layers and components are stacked to form the EPP structure, then the EPP achieves its functional requirements, but the assembly creates potential attack vectors for malicious probing and injection
Solution Approach 1:
The patent uses a flexible layer containing distributed conductive particles as a protective barrier between the user interface and internal components. This thin film structure maintains the necessary functionality for PIN entry while creating a difficult-to-penetrate barrier against probing and injection attacks, as any breach would disrupt the conductive particle network and trigger tamper detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively detects and prevents unauthorized access by monitoring resistance changes across electrode elements, providing enhanced protection against malicious probing and tampering attempts.
Implementation Method 1
the second layer comprises a composite layer, comprising electrically conductive particles combined with an elastomeric binder, to provide the at least one bridge element. Aptly, the composite layer comprises Quantum Tunnelling Composite (QTC) (trade mark) material.
Data Source
AI summary
The present invention provides a method and apparatus for protecting an Encrypting PIN Pad (EPP) against tampering. The apparatus provides an EPP comprising a first layer comprising at least two spaced apart electrode elements, and a second layer comprising at least one bridge element for electrically bridging a space between the at least two electrode elements when the first layer and the second layer are urged together.