Fractal hash sequence representation and traversal

Abstract

We introduce a novel amortization technique for computation of consecutive pre-images of hash chains, given knowledge of the seed. While all previously known techniques have a memory-times-computational complexity of O(n) per chain element, the complexity of our technique can be upper bounded at O(log/sup 2/ n), making it a useful primitive for low-cost applications such as authentication, signatures and micro-payments.