A relay attack is a type of cyber-attack that involves intercepting and relaying communication between two devices or systems. The primary goal is to deceive these devices into believing they are in close proximity, thereby gaining unauthorized access or control. This form of attack is particularly concerning in scenarios where authentication protocols rely on proximity, such as keyless entry systems and contactless payment methods.

Unlike other types of attacks, a relay attack does not require the attacker to view or manipulate the intercepted data. Instead, the attacker simply relays the communication between the two devices, tricking the target system into granting access. This makes relay attacks a significant threat in various technological applications, emphasizing the need for robust security measures to counteract such vulnerabilities.

How do Relay Attacks Work?

Relay attacks operate by intercepting and relaying communication signals between two devices, typically without altering the data. Attackers use specialized equipment to capture signals from a legitimate device, such as a key fob or contactless payment card, and then relay these signals to the target system. This process tricks the system into believing the legitimate device is in close proximity, thereby granting unauthorized access.

The technical process involves several steps. First, the attacker intercepts the signal from the legitimate device. Next, this signal is relayed to another device controlled by the attacker, which then transmits it to the target system. The target system, deceived by the relayed signal, authenticates the communication as if it were coming directly from the legitimate device. This seamless relay of signals allows attackers to bypass security measures that rely on proximity-based authentication.

Devices commonly involved in relay attacks include key fobs for cars, contactless payment cards, and mobile devices. The communication methods exploited often involve Radio Frequency Identification (RFID) and Near Field Communication (NFC) technologies. By leveraging these methods, attackers can effectively bridge the gap between the legitimate device and the target system, enabling unauthorized access without the need for direct manipulation of the intercepted data.

What are Examples of Relay Attacks?

Examples of relay attacks are prevalent in various sectors, notably in automotive and contactless payment systems. In the automotive industry, relay attacks on keyless entry systems have been demonstrated by researchers, such as the 2018 study by the University of Birmingham. They successfully intercepted and relayed signals between a car and its key fob, allowing them to unlock and start the vehicle without the key fob being physically present.

Contactless payment systems are also vulnerable to relay attacks. Security experts have shown that attackers can intercept and relay signals between a contactless payment card or mobile device and the payment terminal. This enables unauthorized transactions by tricking the terminal into processing the payment as if the legitimate card or device is nearby. These examples highlight the diverse applications and potential impact of relay attacks across different technologies.

What are the Potential Risks of Relay Attacks?

Relay attacks pose several significant risks to individuals and organizations. Here are some of the potential risks associated with suffering such an attack:

• Financial Loss Due to Unauthorized Transactions: Attackers can intercept and relay signals between a payment terminal and a contactless card or mobile device, leading to unauthorized payments.

• Compromise of Personal Data and Privacy: Unauthorized access to vehicles or financial systems can expose personal information and sensitive authentication tokens.

• Unauthorized Access to Secure Systems: Attackers can hijack and relay user credentials, gaining access to secure servers and services without proper authorization.

• Potential for Identity Theft: Intercepted credentials from contactless smart cards can be used for unauthorized transactions, leading to identity theft.

• Disruption of Business Operations: Unauthorized access to high-security buildings or systems can lead to significant operational disruptions, including theft of sensitive information or system sabotage.

How can you Protect Against Relay Attacks?

Protecting against relay attacks requires a combination of technological solutions and best practices. Here are some effective measures:

• Use Signal-Blocking Pouches: Store key fobs and contactless cards in Faraday cages or signal-blocking pouches to prevent signal interception.

• Implement Cryptographic Protocols: Utilize cryptographic protocols and time-sensitive codes in keyless entry systems to ensure secure authentication.

• Regular Software Updates: Keep all devices, including key fobs and payment systems, updated with the latest security patches to mitigate vulnerabilities.

• Enable Additional Authentication: Use multi-factor authentication and transaction limits for contactless payments to add an extra layer of security.

• Educate Users: Raise awareness about the risks of relay attacks and promote good security practices, such as manually disabling keyless entry when not in use.