Symmetric Cryptography 2
RSA Conference 2024 · Track Session
This talk delves into the critical, yet often overlooked, multi-user security of **2-Key Triple DES (2K3DES)**. While the Data Encryption Standard (DES) is a legacy cipher, its cascaded variant, 2K3DES, astonishingly remains in active use by several major organizations, including ISO and EMVCo, and is accepted by NIST for legacy decryption. The presentation addresses a significant gap in cryptographic understanding: the lack of a **tight security proof** for 2K3DES in a multi-user setting. Previous analyses provided attack complexities but lacked corresponding security proofs, leaving open the possibility of improved, more efficient attacks.