Multicollision attacks and generalized iterated hash functions

摘要

We apply combinatorics on words to develop an approach to multicollisions in generalized iterated hash functions. Our work is based on the discoveries of A. Joux and on generalizations provided by M. Nandi and D. Stinson as well as J. Hoch and A. Shamir. We wish to unify the existing diverse notation in the field, bring basic facts together, reprove some previously published results and produce some new ones. A multicollision attack method informally described by Hoch and Shamir is laid on a sound statistical basis and studied in detail.