Fault Analysis of Rabbit: Toward a Secret Key Leakage

Although Differential Fault Analysis (DFA) led to powerful applications against public key [15] and secret key [12] cryptosystems, very few works have been published in the area of stream ciphers. In this paper, we present the first application of DFA to the software eSTREAM candidate Rabbit that leads to a full secret key recovery. We show that by modifying modular additions of the next-state function, 32 faulty outputs are enough for recovering the whole internal state in time $\mathcal{O}\left( 2^{34}\right)$ and extracting the secret key. Thus, this work improves the previous fault attack against Rabbit both in terms of computational complexity and fault number.