Fault Attacks on the Authenticated Encryption Stream Cipher MORUS

• DOI: 10.3390/cryptography2010004
• Publication Date: 2018-01-30T17:13:37Z
• Authors: Iftekhar Salam; Leonie Simpson; Harry Bartlett; Ed Dawson; Kenneth Koon-Ho Wong
• Keywords: Technology; T; CAESAR; 02 engineering and technology; forgery; 004; key recovery; fault attack; MORUS; MORUS; CAESAR; authenticated encryption; key recovery; forgery; fault attack; 0202 electrical engineering, electronic engineering, information engineering; authenticated encryption

This paper investigates the application of fault attacks to the authenticated encryption stream cipher algorithm MORUS. We propose fault attacks on MORUS with two different goals: one to breach the confidentiality component, and the other to breach the integrity component. For the fault attack on the confidentiality component of MORUS, we propose two different types of key recovery. The first type is a partial key recovery using a permanent fault model, except for one of the variants of MORUS where the full key is recovered with this model. The second type is a full key recovery using a transient fault model, at the cost of a higher number of faults compared to the permanent fault model. Finally, we describe a fault attack on the integrity component of MORUS, which performs a forgery using the bit-flipping fault model.