When a function is iterated and each time a previous result is used as input to the next iteration (feedback), so that there is a limited benefit from parallel computing, is there such function that:
requires polynomial time to get the result of N iterations
has an Nth result that can be verified in constant time to be the Nth result for a given start value
Assuming that Alice iterates the function:
Problem with Makwa: At first Bob must use and throw away p and q.
Problem with LCS35: At first Bob must construct the puzzle.
But I need a function so that Alice can choose an arbitrary number or data to begin iterating with, not something prepared by Bob. Only when Alice has done N iterations Bob will join and verify.