Fault Injection Attacks For Dummies

Fault injection attacks are a diverse set of techniques used to disrupt the normal behavior of hardware systems, often to circumvent security measures. These attacks can be broadly categorized based on the method used to induce faults. Here's a list of various types of fault injection attacks along with practical case scenarios:

1. Voltage Glitching: Involves momentarily dropping or spiking the power supply voltage to cause computational errors. Example: Attacking a smart card by briefly dropping the voltage can cause it to skip certain security checks, potentially exposing sensitive data.
2. Clock Glitching: Disturbing the clock signal to disrupt the timing of operations. Example: Altering the clock signal of a microcontroller in a gaming console could bypass security checks, allowing the execution of unauthorized code.
3. Electromagnetic Fault Injection (EMFI): Using electromagnetic pulses to induce faults in specific parts of a circuit. Example: Applying an EM pulse to a secure element in a mobile phone to extract encryption keys or bypass PIN verification.
4. Laser Fault Injection: Directing laser beams to specific parts of a chip to induce transient faults. Example: Using a focused laser to disrupt the operation of a CPU in a secure device, such as tampering with the execution of a cryptographic algorithm.
5. Temperature Variation: Extreme cooling or heating to cause faults. Example: Using rapid cooling techniques (like liquid nitrogen) on memory chips to recover data that should have been erased during a normal shutdown process.
6. Power Cycling: Abruptly turning the power off and on to cause errors in memory or logic. Example: Rapidly power cycling a router to interrupt the boot process, potentially allowing access to a boot loader with fewer security restrictions.
7. Rowhammer Attack: Repeatedly accessing memory rows to cause bit flips in adjacent rows. Example: Repeatedly accessing specific areas of DRAM in a computer to induce bit flips that can lead to privilege escalation.
8. Ionizing Radiation: Exposing chips to particles like neutrons, protons, or heavy ions to cause bit flips. Example: In a highly specialized scenario, a secure chip could be exposed to ionizing radiation in a lab setting to alter its behavior or memory content.
9. Acoustic Fault Injection: Using sound waves to cause mechanical vibrations in hardware components.Example: Generating specific sound frequencies to disturb hard disk operations, potentially leading to crashes or malfunctions in a security-critical application.
10. Optical Fault Injection: Using light sources other than lasers, like LEDs or camera flashes, to induce faults. Example: Flashing a bright light into a sensor or photodiode to disrupt its normal operation, potentially causing malfunctions in sensor-dependent security systems.
11. Mechanical Stress: Applying physical force or bending to induce faults. Example: Flexing a smart card to momentarily disrupt its internal connections, potentially bypassing chip-and-PIN verification.

These attacks often require a high level of technical expertise and specialized equipment. They are typically aimed at devices where valuable data can be extracted or where security mechanisms can be bypassed, such as smartphones, smart cards, secure tokens, gaming consoles, and other embedded systems.

To mitigate these attacks, a combination of design, manufacturing, and operational strategies are usually employed:

1. Redundant Hardware Design: Implementing redundant circuits or systems can help detect and correct errors caused by fault injections. This can include using error-correcting code (ECC) memory, which can detect and correct data corruption.
2. Secure Boot and Hardware Root of Trust: Establishing a secure boot process with hardware-based root of trust ensures that only authenticated and integrity-checked code runs on the device. This can prevent unauthorized code execution even if a fault injection attack is successful.
3. Voltage and Clock Glitch Detection: Fault injection often involves tampering with the power supply or clock signal. Hardware that can detect unusual fluctuations in voltage or clock frequency can trigger protective shutdowns or resets.
4. Physical Tamper Detection and Response: Devices can be designed to detect physical tampering, such as attempts to decapsulate the chip or drill into it. Once tampering is detected, the device can erase sensitive data or lock itself down.
5. Sensor Redundancy and Cross-Checking: Implementing multiple sensors for critical measurements, and cross-checking their outputs, can help identify when a sensor reading has been artificially altered through fault injection.
6. Side-Channel Attack Resistance: Fault injection attacks are often combined with side-channel attacks. Hardware designs that reduce side-channel leakage (like power or electromagnetic emissions) make these attacks more difficult.
7. Cryptography with Built-in Fault Resistance: Cryptographic algorithms can be designed to be resistant to fault attacks. For instance, certain implementations of AES can be made resistant to Differential Fault Analysis (DFA).
8. Regular Firmware and Software Updates: Keeping firmware and software up to date can help mitigate fault injection attacks that exploit known vulnerabilities.
9. Physical Shielding and Encapsulation: Physically shielding sensitive components of the hardware can protect against laser fault injections and other physical intrusion methods.
10. Training and Policies: Educating employees about the risks and signs of fault injection attacks is crucial. Establishing policies for secure handling and storage of devices can reduce the risk of physical tampering.
11. Failure Analysis and Forensics: In case of an attack, analyzing how the fault was injected and what part of the hardware was affected can provide insights for improving future designs.
12. Supply Chain Security: Ensuring the integrity of the hardware components throughout the supply chain is critical to prevent tampering before the device reaches the end-user.

Implementing these strategies requires a balance between cost, feasibility, and the level of security required, which can vary depending on the application and the value of the protected assets.

WANNA BECOME A CERTIFIED HARDWARE HACKER?

The Offensive Hardware Hacking Training is a Self-Paced training including Videos, a printed Workbook and a cool Hardware Hacking Kit. And... you get everything shipped home Worldwide!?

For more info: ? https://www.whid.ninja??