Side-channel attacks exploit information leaked from a
smart card or other system through unintended means. In general, unless great
care has been taken to reduce or eliminate side-channel leakage, a smart card
constantly leaks significant information about its internal state.
Readily exploited side-channels include
- Unintentional functionality and design errors
resulting in leaked information
- Data-dependent processing time (useful in timing
attacks)
- Identifiable patterns in current-consumption
waveform (useful in SPA – Simple Power Analysis)
- Minute data-dependent variations in waveforms
(useful in DPA – Differential Power Analysis)
- Potentially even Radio Frequency radiation from a
PC, remotely monitored.
The best-known forms of attacks include
- Timing attacks, particularly on message
authentication codes and public key systems (e.g. RSA)
- SPA attacks (identifying the sequence of operations
from patterns in current-consumption waveform)
- DPA attacks that rely on a leakage of a logical
function of both known varying data and the key
A further form of attack closely related to DPA -
a matching or template attack - targets any data-dependent
waveforms. This attack can be far more sensitive that a typical DPA attack and
can readily extract information from operations as simple as data movement.
It represents a serious security threat in cryptographic tokens (smart cards,
especially Pay-TV, banking and GSM).
CypheRix has expertise in
- System-wide cryptographic strength
- Design and development for resistance against all
known attacks
- Comprehensive testing for correctness of
implementation
- Formal (provable) approaches and solutions to DPA
resistance
- Assessing designs for side-channel vulnerabilities
- Re-engineering implementations for SPA and DPA
resistance
