This discloses, in the computer data security field, a cryptographic hash function process embodied in a computer system and which may be keyless, but is highly secure. The process is based on the type of randomness exhibited by a heap or stack of physical objects such as a heap of pieces of fruit and involves modeling the behavior of such a heap when pieces are removed from the heap. Computation of the hash value (digest) is thereby the result of executing a heap model algorithm using the message as an input to initialize the heap, then executing the heap model algorithm which logically models the process of serially removing objects (pieces of fruit) from the heap at various locations in the modeled heap.