Template Attack Against AES in Counter Mode With Unknown Initial Counter
Marcial Tienteu, Edmund Smith, Edgar Mateos Santillan, Kevin Kornegay, Paige Harvey, Otily Toutsop, Tsion M. Yimer, Vinton Morris, Ketchiozo Wandji · 2023
Despite long-contested viability, numerous applications still rely upon Advance Encryption Standard (AES) in Counter mode (AES-CTR). Research supports that the vulnerabilities associated with CTR from a mathematical perspective, mainly forgery attempts, stem from misusing the nonce. When paired with cryptographic algorithms, assuming no nonce misuse increases the complexity of unraveling CTR. This paper examines the pairing of CTR with AES-128 (AES-CTR). It includes (1) full key recovery for a software implementation of AES-CTR utilizing a template attack (TA) and (2) enhancing the TA analysis's point of interest (POI) using first-order analysis and known key to identify leaky samples.