Introduction to differential power analysis

TLDR

Power consumption varies with circuit activity, so measuring it reveals information about operations and data, challenging the assumption that cryptographic designs expose no side‑channel information. The paper investigates how power‑based side‑channel leakage can be exploited to recover secret keys and proposes countermeasures to prevent such attacks. The authors propose countermeasures and design principles to build hardware‑resilient cryptosystems against DPA attacks. The study demonstrates that DPA attacks are practical, non‑invasive, and highly effective even on noisy, complex systems where cryptographic operations contribute only a small portion of total power.

Abstract

The power consumed by a circuit varies according to the activity of its individual transistors and other components. As a result, measurements of the power used by actual computers or microchips contain information about the operations being performed and the data being processed. Cryptographic designs have traditionally assumed that secrets are manipulated in environments that expose no information beyond the specified inputs and outputs. This paper examines how information leaked through power consumption and other side channels can be analyzed to extract secret keys from a wide range of devices. The attacks are practical, non-invasive, and highly effective—even against complex and noisy systems where cryptographic computations account for only a small fraction of the overall power consumption. We also introduce approaches for preventing DPA attacks and for building cryptosystems that remain secure even when implemented in hardware that leaks.