Cryptanalysis of Submission to the CAESAR Cryptographic Competition iFeed

iFeed is a blockcipher-based authenticated encryption design by Zhang, et al. [81] and a candidate to the CAESAR competition. iFeed is claimed to achieve confidentiality and authenticity in the nonce-respecting setting, and confidentiality in the noncereuse setting. In this thesis, we consider the security of iFeed in three settings. In the noncerespecting setting we show a forgery and subkey recovery attack with only one encryption query. In the nonce-misuse setting we show a forgery, subkey recovery, and distinguishing attack. Also in the RUP setting we show a subkey recovery attack. With the subkey obtained in these attacks, we can decrypt earlier and future encryptions, which leads to a total security compromise of iFeed.