Combating Side-Channel Attacks Using Key Management

Embedded devices are widely used in military and civilian operations. They are often unattended, publicly accessible, and thus vulnerable to physical capture. Tamper-resistant modules are popular for protecting sensitive data such as cryptographic keys in these devices. However, recent studies have shown that adversaries can effectively extract the sensitive data from tamper-resistant modules by launching semi-invasive side-channel attacks such as power analysis and laser scanning. This paper proposes an effective key management scheme to harden embedded devices against side-channel attacks. This technique leverages the bandwidth limitation of side channels and employs an effective updating mechanism to prevent the keying materials from being exposed. This technique forces attackers to launch much more expensive and invasive attacks to tamper embedded devices and also has the potential of defeating unknown semi-invasive side-channel attacks. 1