Cryptography Reference
In-Depth Information
Chapter 1
Side-Channel Analysis and Its Relevance
to Fault Attacks
Elisabeth Oswald and François-Xavier Standaert
Abstract
Side-channel attacks are a class of attacks where an attacker deduces the
internal state of a device by observing information that leaks during the normal
functioning of the device. In this chapter we describe side-channel analysis and its
relevance to fault attacks. Side-channel analysis is typically used to extract informa-
tion about cryptographic keys. However, we will be concentrating on how it can be
used as a means to identify target operations and as a trigger mechanism for fault
attacks.
1.1 Introduction
Side-channel attacks are a class of attacks where an attacker will attempt to deduce
what is occurring inside a device by observing information that leaks during the
normal functioning of the device. The first publication that mentions a side-channel
attack is [422]. In 1956, MI5 mounted an operation to decipher communications
between Egyptian embassies. The communications were enciphered using Hagelin
machines [207]. Enciphering occurred by routing electronic signals from a keyboard
through seven rotating wheels to generate a ciphertext. The “key” was the initial
setting of these seven wheels. The machine was reset every morning by the clerk
