Motherboard’s Michael Byrne recently covered a paper written by Rambus chief scientist Paul Kocher for Communications of the ACM. In the paper, Kocher observes that computer security issues have far exceeded the limits of the human brain. To illustrate his point, the chief scientist points to Ohio’s infamous Silver Bridge, which collapsed during rush hour in 1967.
“Instead of redundancy, the bridge used high-strength steel. The failure of a single eyebar was catastrophic. Today’s computing devices resemble the Silver Bridge, but are much more complicated,” Kocher explained. “They have billions of lines of code, logic gates, and other elements that must work perfectly. Otherwise, adversaries can compromise the system. The individual failure rates of many of these components are small, but aggregate complexity makes vulnerability statistically certain.”
As Bryne notes, Kocher views computer security as a scaling problem.
“While the complexity of our machines increases exponentially, the development of new, reliable security schemes has not kept pace. Instead, security engineers take comfort in the complexity itself,” he writes. “That is, we make claims about the strength of our (weak) digital defenses based simply on not knowing which elements may actually fail. We can build a solid-looking bridge, jump up and down on it a few times, and call it safe—but this isn’t nearly the same thing as going through the bridge piece by piece and testing every possible (excessive) force on every one of them individually. To engineers, it might just look futile.”
Kocher’s solutions, say Bryne, are focused on dedicated, quarantined and simple hardware.
“In the mid-’90s, Kocher and colleagues were able to produce some statistical techniques that can be used to crack security protocols by monitoring variations in CPU power consumption or radio frequency fluctuations – what’s generally known as a side-channel attack. Things haven’t improved much,” he continues. “[The] key to making it all work is in building new hardware security building blocks simple enough for real-world engineers to understand. That is, complexity is itself an inherent danger in crafting tools to fight complexity.”
According to Bryne, the progression of computing systems can be thought of as a total crush of new features: more cores, deeper memory architectures [and] sensors for everything.
“Every new interaction between elements within a system represents a new security risk, and, as Kocher explains, risks will in the worst case increase as the square of the total number of components within a system. If my computing system has 100 components, it has 10,000 vulnerabilities,” Bryne concludes.