31st Fast Software Encryption Conference

Title

Stream Ciphers Strike Back

Abstract

At Asiacrypt 2004, Adi Shamir gave an invited talk entitled "Stream ciphers: dead or alive?", in which he posed the question of the relevance of dedicated stream cipher designs. He concluded that stream ciphers were in an unavoidable long-term decline, but that they may survive in some niche applications. Indeed, dedicated stream ciphers and their cryptanalysis have not attracted a lot of attention from the research community in the last 15 years, once the eSTREAM project has ended.
However, such designs have recently emerged as suitable candidates for transciphering, i.e., for combination with an FHE scheme in order to address the ciphertext expansion problem. The reason for this is that dedicated stream ciphers seem to be cheaper to evaluate homomorphically than block-cipher designs. In this talk, we will discuss the performance metrics and relevant designs for transciphering, and revisit some classical results in this particular context.

Biography

Anne Canteaut is a French researcher in cryptography, working at the French Institute for Research in Computer Science and Control (INRIA) in Paris. She has chaired the INRIA Evaluation Committee, and the FSE steering committee.
Her main research interest include symmetric cryptography, sequences and finite fields. Most notably, her work focuses on the analysis of the mathematical properties of the building-blocks in symmetric primitives and on their impact on security. She is also the co-designer of several cryptographic primitives.

Title

Two Decades of CMAC

Abstract

In 2005, NIST adopted CMAC, Cipher-based Message Authentication Code, as a recommended block cipher mode of operation in NIST SP 800-38B. CMAC contributes to a wide range of real-world applications; NIST Cryptographic Algorithm Validation Program (CAVP) lists more than 2,000 implementations of CMAC by various vendors. This talk will revisit the early history of development, review various research results related to this MAC, and introduce the latest research regarding the use of CMAC in key derivation functions.

Biography

Tetsu Iwata is professor at Nagoya University, Japan. He works on the design and analysis of symmetric key cryptosystems, and in recent years, he is also interested in their quantum security. He co-designed CMAC (Cipher-based Message Authentication Code), which was adopted by NIST as a recommended block cipher modes of operation in NIST SP 800-38B in 2005. He received the best paper awards of FSE 2015 and CRYPTO 2019, and the test-of-time awards for the papers from FSE 2006 and FSE 2007.