Framework for Fast Memory Authentication Using Dynamically Skewed Integrity Tree

Abstract

Integrity trees are widely used in computer systems to prevent replay, splicing, and spoofing attacks on memories. Such mechanisms incur excessive performance and energy overhead. We propose a memory authentication framework that combines architecture-specific optimizations of the integrity tree with mechanisms that enable it to restructure at runtime based on memory access patterns. The integrity tree structure is customized based on the cache configuration in order to minimize the performance and energy overhead through speculative authentication. At runtime, the tree nodes that are accessed more frequently will be dynamically shifted closer to the root such that fewer levels of the tree are accessed during authentication. The framework is simulated with Multi2Sim and compared with other existing mechanisms [i.e., tamper-evident counter (TEC) tree and ASSURE] to demonstrate its performance and energy benefits. Experimental results using benchmarks from SPEC-CPU2006, SPLASH-2, and PARSEC show that the proposed dynamic integrity tree leads to an average reduction in instruction per cycle of 13% and 10% over TEC tree and ASSURE, respectively. The corresponding average reduction in authentication time is 30% and 20%, respectively. We show that the proposed framework facilitates the selection of a processor with a smaller cache size such that the energy consumption is reduced without sacrificing performance.