The paper “Key Committing Security of HCTR2, Revisited” has been accepted at the Crypto 2026 conference. This is the longest-running cryptography conference, and has been held every year since 1981 in Santa Barbara, California, USA.
This paper presents improved attacks and proofs for the key committing security of EtE-HCTR2, a robust authenticated encryption scheme constructed from HCTR2 and the Encode-then-Encipher (EtE) framework, in light of the ongoing standardization effort of cryptographic accordions by NIST.
It is co-authored by Donghoon Chang, Yu Long Chen, Yukihito Hiraga, Kazuhiko Minematsu, Nicky Mouha (Founder of KeyCryptic), Yusuke Naito, Yu Sasaki, and Takeshi Sugawara.