D.: A library for removing cache-based attacks in concurrent information flow systems: Extended version. http://www.cse.chalmers.se/∼buiras/resLIO.html

Abstract. Information-flow control (IFC) is a security mechanism con-ceived to allow untrusted code to manipulate sensitive data without com-promising confidentiality. Unfortunately, untrusted code might exploit some covert channels in order to reveal information. In this paper, we focus on the LIO concurrent IFC system. By leveraging the effects of hardware caches (e.g., the CPU cache), LIO is susceptible to attacks that leak information through the internal timing covert channel. We present a resumption-based approach to address such attacks. Resumptions pro-vide fine-grained control over the interleaving of thread computations at the library level. Specifically, we remove cache-based attacks by enforc-ing that every thread yield after executing an “instruction, ” i.e., atomic action. Importantly, our library allows for porting the full LIO library— our resumption approach handles local state and exceptions, both fea-tures present in LIO. To amend for performance degradations due to the library-level thread scheduling, we provide two novel primitives. First, we supply a primitive for securely executing pure code in parallel. Sec-ond, we provide developers a primitive for controlling the granularity of “instructions”; this allows developers to adjust the frequency of context switching to suit application demands.