EO-Shield: A Multi-function Protection Scheme against Side Channel and Focused Ion Beam Attacks

Smart devices, especially Internet-connected devices, typically in-corporate security protocols and cryptographic algorithms to en-sure the control flow integrity and information security. However, there are various invasive and non-invasive attacks trying to tam-per with these devices. Chip-level active shield has been proved to be an effective countermeasure against invasive attacks, but existing active shields cannot be utilized to counter side-channel attacks (SCAs). In this paper, we propose a multi-function protection scheme and an active shield prototype to against invasive and non-invasive attacks simultaneously. The protection scheme has a complex active shield implemented using the top metal layer of the chip and an information leakage obfuscation module under-neath. The leakage obfuscation module generates its protection patterns based on the operating conditions of the circuit that needs to be protected, thus reducing the correlation between electromag-netic (EM) emanations and cryptographic data. We implement the protection scheme on one Advanced Encryption Standard (AES) circuit to demonstrate the effectiveness of the method. Experiment results demonstrate that the information leakage obfuscation mod-ule decreases SNR below 0.6 and reduces the success rate of SCAs. Compared to existing single-function protection methods against physical attacks, the proposed scheme provides good performance against both invasive and non-invasive attacks.