Advances in NIST Symmetric-Key Standards: Ascon, Accordion, and Beyond (G22c)
This talk presents updates on several NIST efforts on symmetric-key cryptography, including the Lightweight Cryptography (LWC) project, the Accordion project, and new work on possible standardization of wide block ciphers. It summarizes the status of the LWC standardization effort, highlighting the selection of Ascon as the lightweight cryptography standard and ongoing efforts to support deployment in constrained environments. This talk also introduces Accordion, a new initiative that develops flexible, authenticated-encryption modes tailored to diverse security and performance needs. Design goals, security analyses, and the relationship to existing NIST-approved modes such as the SP 800-38 series and Ascon-AEAD are outlined. Finally, this talk updates the community on NIST’s exploration of Rijndael with 256-bit blocks (Rijndael-256), motivated by feedback on block-cipher modes and growing data-processing demands.