In this work, we present the first practical fault attacks on several nonce-based authenticated encryption modes for AES. This includes attacks on the ISO/IEC standards GCM, CCM, EAX, and OCB, as well as several second-round candidates of the ongoing CAESAR competition. All attacks are based on the Statistical Fault Attacks by Fuhr et al., which use a biased fault model and just operate on collections of faulty ciphertexts. Hereby, we put effort in reducing the assumptions made regarding the capabilities of an attacker as much as possible. In the attacks, we only assume that we are able to influence some byte (or a larger structure) of the internal AES state before the last application of MixColumns, so that the value of this byte is afterwards non-uniformly distributed.
In order to show the practical relevance of Statistical Fault Attacks and for evaluating our assumptions on the capabilities of an attacker, we perform several fault-injection experiments targeting real hardware. For instance, laser fault injections targeting an AES co-processor of a smartcard microcontroller, which is used to implement modes like GCM or CCM, show that 4 bytes (resp. all 16 bytes) of the last round key can be revealed with a small number of faulty ciphertexts.Category / Keywords: secret-key cryptography / fault attacks, authenticated encryption, CAESAR, statistical fault attacks Original Publication (in the same form): IACR-ASIACRYPT-2016 Date: received 13 Jun 2016, last revised 13 Sep 2016 Contact author: florian mendel at iaik tugraz at Available format(s): PDF | BibTeX Citation Version: 20160913:071744 (All versions of this report) Short URL: ia.cr/2016/616 Discussion forum: Show discussion | Start new discussion