DFA Mechanism on the AES Key Schedule

• Published in: Workshop on Fault Diagnosis and Tolerance in Cryptography : FDTC 2007 : proceedings : 10 September, 2007, Vienna, Austria pp. 62 - 74
• Main Authors: Takahashi, J., Fukunaga, T., Yamakoshi, K.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.09.2007
• Subjects: Algorithm design and analysis; Cryptography; Doped fiber amplifiers; Equations; Fault diagnosis; Information analysis; Laboratories; Processor scheduling; Telegraphy; Telephony
• ISBN: 0769529828; 9780769529820
• DOI: 10.1109/FDTC.2007.13

This paper describes a DFA (differential fault analysis) mechanism on the AES key scheduling process and shows how an entire 128-bit AES key can be retrieved. We make a detailed analysis of the DFA mechanism on the AES key schedule and propose general attack rules. As a result of reconsidering the best attack approach on the basis of analysis, we present a more efficient attack than the previous one. We show that we can retrieve an entire 128-bit AES key using 2-pairs of correct and faulty ciphertexts with a 48-bit brute-force search, 4-pairs of them with a 16-bit brute-force search and 7-pairs of them without brute-force search. These steps are enough to calculate the key with feasible computation resources.