Side Channel Attacks on Cryptographic Implementations
Subject Area: Cryptography and Network Security
Presenter: Prof. INDRANIL SENGUPTA
Indian Institute of Technology, Kharagpur
Kharagpur 721302, INDIA
Duration:
60 minutes
Abstract
The talk will emphasize on side-channel attack on cryptographic implementations, with particular
emphasis on timing and power analysis attacks. Side-channel attacks have become very important in
today’s security scenario, where an otherwise secure algorithm becomes vulnerable with respect to its
implementation. Starting with some basics on network security and cryptography, some practical sidechannel attacks will be discussed, followed by some countermeasures and some guidelines for secure
implementations.
It is an extremely important and difficult task to assess the security of a system. Even in a well-designed
system, there can be security loopholes through abusing protocols, choice of inadequate parameters,
non-perfect implementations of cryptographic algorithms, etc. It is a great challenge of security
engineering to design systems in which each of these factors are handled correctly. Attacks on systems
are quite common, and a large amount of time and effort is being put in to thwart them. Traditional
cryptanalysis has been in place for several decades, where one tries to break a code or cryptosystem
using available information. In recent years, a new class of attacks on cryptographic implementations,
called side-channel attacks, have been proposed and investigated (Ref: Kocher et al, 1998).
A side channel attack is any attack based on information gained from the physical implementation of a
cryptosystem, rather than theoretical weaknesses in the algorithms. For example, timing information,
power consumption, electromagnetic leaks or even data coming out of scan chains used for testing can
provide an extra source of information which can be exploited to break the system. Many side-channel
attacks require considerable technical knowledge of the internal operation of the system on which the
cryptography is implemented. Among the various types of side-channel attacks, the talk will in particular
concentrate on power and timing attacks, which try to analyze the variations in the current drawn and
the time taken during the various cryptographic steps, to gain insight into some secret information (e.g.,
the key). Under this class of attacks, even an algorithm that has been known to be safe becomes
vulnerable due to faulty implementations.