Lakshminarasimhan Sethumadhavan

Rapid Parallelization by Collaboration

The widespread adoption of Chip Multiprocessors has renewed the emphasis on the use of parallelism to improve performance. The present and growing diversity in hardware architectures and software environments, however, continues to pose difficulties in the effective use of parallelism thus delaying a quick and smooth transition to the concurrency era. In this document, we describe the research being conducted at Columbia University on a system called COMPASS that aims to simplify this transition by providing advice to programmers considering parallelizing their code. The advice proffered to the programmer is based on the wisdom collected from programmers who have already parallelized some code. The utility of COMPASS rests, not only on its ability to collect the wisdom unintrusively but also on its ablility to automatically seek, find and synthesize this wisdom into advice that is tailored to the code the user is considering parallelizing and to the environment in which the optimized program will execute in. COMPASS provides a platform and an extensible framework for sharing human expertise about code parallelization – widely, and on diverse hardware and software. By leveraging the “wisdom of crowds” model [78] which has been conjunctured to scale exponentially and which has successfully worked for wikis, COMPASS aims to enable rapid parallelization of code and thus continue to extend the benefits of Moore’s law scaling to science and society. ACM

Cost and Scalability of Hardware Encryption Techniques

We discuss practical details and basic scalability for two recent ideas for hardware encryption for trojan prevention. The broad idea is to encrypt the data used as inputs to hardware circuits to make it more difficult for malicious attackers to exploit hardware trojans. The two methods we discuss are data obfuscation and fully homomorphic encryption (FHE). Data obfuscation [5] is a technique wherein specific data inputs are encrypted so that they can be operated on within a hardware module without exposing the data itself to the hardware. FHE is a technique recently discovered to be theoretically possible [2]. With FHE, not only the data but also the operations and the entire circuit are encrypted. FHE primarily exists as a theoretical construct currently. It has been shown that it can theoretically be applied to any program or circuit [2]. It has also been applied in a limited respect to some software [4]. Some initial algorithms for hardware applications have been proposed [1]. We find that data obfuscation is efficient enough to be immediately practical, while FHE is not yet in the practical realm. There are also scalability concerns regarding current algorithms for FHE.