Paul Kocher, the chief scientist of Rambus’ Cryptography Research division, recently presented a DesignCon 2016 keynote session that explored the crowded intersection of hardware, Moore’s Law and cryptography. As Kocher notes, cryptographic limits have historically been constrained by a salient lack of computing power.
“[Following Moore’s Law], more computing power enables much stronger algorithms,” he explained. “[Concurrently], more robust computing power has also led to an increasing number of security breaches at all levels. In fact, within two years, approximately 90% of all IT networks will experience an IoT-based security breach.”
This trend of insecurity can only be expected to continue, says Kocher, with analysts forecasting some 50 billion connected devices by 2020.
“There will be more devices, more valuable data and more complexity. What does this mean for attackers? More targets, reward and vulnerabilities,” he continued. “[As such], it is important to realize that security is fundamentally different from functionality. The former requires very different engineering strategies and assumptions.”
Incorrect assumptions, warns Kocher, often leads to negative outcomes.
“One could falsely assume hardware and software logic will be bug free. However, the reality is that current devices are one to three exploits away from total breach, with overwhelming likelihood of vulnerabilities at each layer,” the chief scientist confirmed. “SoCs are usually just one bug away from ruining software protections.”
One such vulnerability highlighted by Kocher during the keynote session was side-channel attacks.
“The [typical] assumption is that attackers only see the binary input/output data. The reality? Power & RF measurements show tiny correlations to individual gates,” he explained. “The information content of a secret key is tiny (typically 128-2K bits). Information can be extracted from noisy channels. The attack [vector] is to measure, divide into subsets and compare subset average.”
According to Kocher, the price of maintaining the insecurity status quo is steadily increasing due to FTC actions, litigation, insurance costs and various regulatory risks. In contrast, hardware-based security offers manufacturers a number of benefits, including deterrence against physical theft, optimized inventory management (chips can be configured and re-configured) and a separate IPR license for global trade (with configuration codes generated after import).
“Robust security will eventually be required – often for many use cases, such as DRMs, payment schemes, credential systems and device keys. [Plus], falling transistor costs – as per Moore’s Law – means lower per-chip manufacturing cost for security features,” he explained. “Moreover, it is important to remember that [stand-alone] software security doesn’t scale and there is no hope of eliminating bugs in existing software. The situation is getting worse, not better, as patching is expensive and not very effective.”
Separate chips, says Kocher, can help, although designers should be aware of the associated impact on cost, performance, size and power draw. In addition, interfaces – between the security and other chips – can themselves be vulnerable.
“Secure ‘on-SoC’ logic blocks are better, as they are isolated from the main processor and all of its software by an intra-chip security perimeter. In short, they are more cost effective and offer better security,” Kocher explained.
“[This is precisely why] the Cryptography Research division of Rambus designed the CryptoManager core to protect and deliver keys and configuration settings for use throughout an SoC’s hardware and software [layers]. Meanwhile, the CryptoManager server (or service) delivers keys and authorizations to factories or data centers and audits usage.”
The current generation of hardware, Kocher concludes, provides a rather poor foundation for consumer security.
“It is built with incorrect assumptions about software quality. The technology industry’s impact depends on finding solutions. Otherwise, the lack of security will erase net benefits from new technology such as the IoT,” he added.