Position: Ph.D. Candidate

Current Institution: University of Maryland, College Park

Ideal Ciphers: A Closer Look

Block ciphers are an important building block in many cryptographic constructions. Such constructions are often designed and analyzed in an idealized framework called the ideal-cipher model where the underlying primitive, the block cipher, is modeled as the ideal object, the ideal cipher. (Informally, an ideal cipher is an oracle that takes a key such that each key to the ideal cipher defines an independent, random permutation.)

In this work, I focus on the ideal cipher model and address the following questions: (1) how to construct an ideal cipher and (2) how to reason about security of a block cipher-based cryptographic construction that is instantiated with a “defective” ideal cipher. I discuss approaches to solving these two problems and propose research directions aimed at understanding the security provided by current approaches to block cipher designs.

Aishwarya Thiruvengadam is a Ph.D. candidate in the Department of Computer Science at the University of Maryland where she is advised by Prof. Jonathan Katz. Her primary interests lie in cryptography and recently, she has been interested in the study and analysis of primitives used in
symmetric-key cryptography.