| Title | : | Security of Classical Approaches to Block Cipher Design |
| Speaker | : | Aishwarya Thiruvengadam (TU Darmstadt) |
| Details | : | Thu, 14 Nov, 2019 2:00 PM @ AM Turing Hall |
| Abstract: | : | Block ciphers are an essential ingredient of modern cryptography. They are widely used as building blocks in many cryptographic constructions. A classical paradigm for block cipher design is the key-alternating cipher (which is encompassed by the popular substitution-permutation network). The key-alternating cipher is an iterated structure that involves applications of random-looking permutations over many rounds. An important area of research is to understand the provable security guarantees offered by classical design paradigms for block cipher constructions. This can be done using a security notion called indiff erentiability which formalizes what it means for a block cipher to be ideal. In this talk, I'll show that a 5-round key-alternating cipher (also known as the iterated Even-Mansour construction) with identical round keys behaves as an ideal block cipher when the round permutations are independent, public random permutations. |
