Multi-Property-Preserving Hash Domain Extension: The EMD Transform

In this paper we (1) argue the benefits of replacing the current MD transform with a multi-property-preserving domain extension transform that guarantees numerous properties of the hash function assuming they hold of the compression function; (2) provide a practical, proven-secure multi-domain extension transform suitable for use with the next generation of hash functions; (3) point to some subtle weaknesses in the transforms of Coron et al. [9] that imply they are not only not suitable multi-property transforms but in fact in some ways provide lower security guarantees than even the current MD transform.