I am trying to find a symmetric cipher that is explicitly designed to be slow. I realize that this is generally not desirable, but I'd like many cycles and lots of electronic action. I could modify a cipher make a Fiestel network have a million rounds, but I'm trying to find something "provably slow" that is akin to a memory-hard function but without the memory.
The motivation for this is that I want a structured way to create test vectors for an asynchronous IC library that are "random-looking" but repeatable for simulation. It's an easy way for me to keep track and cut up the problem on the cluster. The reason that I don't want to use a hash function is architectural. I want to structure of a key schedule and data schedule with a dependency.
Has anyone ever come across a symmetric cipher design to be slow?