📑 Table of Contents▼

Differential fault analysis (DFA) is a type of active side-channel attack in the field of cryptography, specifically cryptanalysis. The principle is to induce faults—unexpected environmental conditions—into cryptographic operations to reveal their internal states.

Principles

edit

Taking a smartcard containing an embedded processor as an example, some unexpected environmental conditions it could experience include being subjected to high temperature, receiving unsupported supply voltage or current, being excessively overclocked, experiencing strong electric or magnetic fields, or even receiving ionizing radiation to influence the operation of the processor. When stressed like this, the processor may begin to output incorrect results due to physical data corruption, which may help a cryptanalyst deduce the instructions that the processor is running, or what the internal state of its data is.[1][2]

For DES and Triple DES, about 200 single-flipped bits are necessary to obtain a secret key.[3] DFA has also been applied successfully to the AES cipher.[4]

Many countermeasures have been proposed to defend from these kinds of attacks. Most of them are based on error detection schemes.[5][6]

Fault injection

edit

A fault injection attack involves stressing the transistors responsible for encryption tasks to generate faults that will then be used as input for analysis. The stress can be an electromagnetic pulse (EM pulse or laser pulse).

Practical fault injection consists of using an electromagnetic probe connected to a pulser or a laser generating a disturbance of a similar length to the processor's cycle time (of the order of a nanosecond). The energy transferred to the chip may be sufficient to burn out certain components of the chip, so the voltage of the pulser (a few hundred volts) and the positioning of the probe must be finely calibrated. For greater precision, the chips are often decapsulated (chemically eroded to expose the bare silicon).[7]

References

edit
  1. ^ Eli Biham, Adi Shamir: The next Stage of Differential Fault Analysis: How to break completely unknown cryptosystems (1996)
  2. ^ Dan Boneh and Richard A. DeMillo and Richard J. Lipton: On the Importance of Checking Cryptographic Protocols for Faults, Eurocrypt (1997)
  3. ^ Ramesh Karri, et al.: Fault-Based Side-Channel Cryptanalysis Tolerant Rijndael Symmetric Block Cipher Architecture (2002)
  4. ^ Christophe Giraud: DFA on AES (2005)
  5. ^ Xiaofei Guo, et al.: Invariance-based Concurrent Error Detection for Advanced Encryption Standard (2012)
  6. ^ Rauzy and Guilley: Countermeasures against High-Order Fault-Injection Attacks on CRT-RSA (2014) (Open Access version)
  7. ^ "Fault Injection". eshard.com. 2021-11-01. Retrieved 2021-11-23.


Stub icon

This cryptography-related article is a stub. You can help Wikipedia by adding missing information.

📚 Artikel Terkait di Wikipedia

Side-channel attack

computation (rather like power analysis). Differential fault analysis – in which secrets are discovered by introducing faults in a computation. Data remanence –

DFA

a finite state machine accepting finite strings of symbols Differential fault analysis, in cryptography, a type of side channel attack Dual factor authentication

Advanced Encryption Standard

attack on some hardware implementations was published that used differential fault analysis and allows recovery of a key with a complexity of 232. In November

Eli Biham

Barkan and Nathan Keller) Co-invention of related-key attacks. Differential Fault Analysis - joint work with Adi Shamir Conditional Linear Cryptanalysis

Widevine

David Buchanan claimed to have broken Widevine L3 through a differential fault analysis attack in Widevine's white-box implementation of AES-128, allowing

Diagnosis

intelligence) Event correlation Fault management Fault tree analysis Grey problem RPR problem diagnosis Remote diagnostics Root cause analysis Troubleshooting Unified

Outline of cryptography

Known-plaintext Side channel attacks Power analysis Timing attack Cold boot attack Differential fault analysis Network attacks Man-in-the-middle attack

White-box cryptography

1007/978-3-030-03329-3_13. ISBN 978-3-030-03328-6. Ezepue, B.C. (2017). "Differential fault analysis of white-box cryptographic implementations". Master Thesis. Seker