Understanding Side Channel Attacks in Crypto Cores
A side channel attack involves observing fluctuations in power while a circuit card operates normally. Specifically, we focus on measuring side channel resistance related to power, a technique known as Single Power Analysis (SPA) or Dual Power Analysis (DPA).
It's akin to placing a microphone next to the circuit and monitoring power or other emanations. By collecting millions of traces of these power fluctuations, a threat actor is able to deduce the encryption key and see data in the clear.
Consequences of Inadequate Side Channel Resistance
If we rewind a decade, the process of extracting a crypto key was mainly confined to universities and national-level laboratories. They'd spend weeks, months, even years accumulating traces before obtaining any meaningful results.
However, advancements in AI and the sensitivity of measuring equipment have revolutionized this landscape. AI, in particular, has empowered attackers to gather vast amounts of traces swiftly.With around $100,000 worth of equipment, readily accessible to many institutions, bad guys can now procure a million traces in a day, a stark contrast to the year-long endeavor it once was. This exponential leap inefficiency underscores the escalating sophistication of side channel attacks.
Consider a scenario involving a radar system installed on an aircraft. This radar system is enclosed within a secure box.However, if the aircraft is shot down, or if the box undergoes maintenance and ends up in a shared facility, such as a Chinese warehouse, there's a risk it could fall into the wrong hands. Imagine it finds its way onto a workbench in Iran or China, or any unfriendly territory. In such a situation, adversaries could exploit the system by capturing measurements while it operates. These measurements would reveal any inadequacies in its protections. By repeatedly capturing these measurements and reverse-engineering the crypto key, they could essentially render the radar system vulnerable, operating it as if it were unencrypted.
This presents a grave concern. Adversaries gain insight into how our radars function, the frequencies they operate on, how we process information, and even how we detect threats in our vicinity. Such knowledge jeopardizes the safety of our military personnel, placing them in imminent danger.
Strategies for Side Channel Resistance
To defend against side channel attacks targeting your actual crypto key, there are effective methods available, one of which is called masking. This technique involves intentionally scrambling some of the power emanations generated during the operation of the device. By doing so, these emanations are no longer correlated with the encryption key.Essentially, even if an attacker captures traces, they won't be able to correlate them to the encryption key. Since they can't crack the key, your information remains secure. You can liken this process to adding noise to the signal, obscuring any meaningful patterns that could be exploited by attackers.
Evolving Threat Landscape
The prevalence of side channel attacks is on the rise due to the diminishing cost and time required for the attack vector.This makes it a much more accessible method for adversaries. It's no longer confined to large military-grade equipment; now, even everyday devices like cell phones are susceptible, especially since they often store sensitive information. Consequently, we're witnessing an uptick in side channel protections from major players like Samsung and Apple, as well as other industries. This includes IoT devices, mobile devices, and control systems for critical infrastructure, such as the electrical grid, even those located in remote areas. Failing to secure these systems could potentially grant hackers access to critical infrastructure, posing a significant threat to security.
Conclusion
The imperative for side channel resistance in cryptographic systems cannot be overstated. As cyber threats advance in sophistication, the need for robust defenses against side channel attacks becomes ever more pressing. Techniques like masking offer effective safeguards,but continued vigilance and innovation are essential to stay ahead of evolving threats. By prioritizing side channel resistance, we can bolster the security of cryptographic systems, safeguard sensitive data, and mitigate the risks posed by cyber adversaries in an increasingly interconnected digital world.
Author Bio
Having spent 25 years in defense, Dan Herway has worn many hats – engineer, program manager, business developer, field engineer – you name it. From designing systems to witnessing their deployment in Iraq and Afghanistan, Dan’s journey has granted him a unique perspective on the technologies we create and how they're utilized by the military.
Dan’s journey into security began at the Idaho National Lab, where he delved into industrial control systems. In 2021, Dan transitioned to Idaho Scientific,focusing heavily on embedded cybersecurity. Although Dan is an engineer at heart, his roles have varied over time. Presently, he serves as the executive vice president at Idaho Scientific, where he oversees corporate strategy,product development, and program management.
