HTree: Hardware Trojan Attack on Cache Resizing Policies

Modern chipmultiprocessors (CMPs) use third-party intellectual properties (IPs) to reduce design costs and meet deadlines. The cores in the CMP has their own private cache memories and all the cores share a common large sized last level cache (LLC). All the components of CMP, including cores and cache memories, are connected through a network-on-chip (NoC). Most of the NoC components have third-party IPs. Some of these IPs may be malicious and act as Hardware Trojan (HT). In this letter, we propose an HT-base attack that targets the LLC resizing techniques. The LLC resizing techniques are used to reduce the energy consumption of the LLC by shutting down unused parts of the LLC. The proposed attack can misuse the properties of these resizing techniques to reduce their energy saving up to 58%. The proposed attack can also reduce the system performance up to 18%.