Method for constructing reinforced hash function based on compression function

TL;DR: In this article, the authors proposed a method for reinforcing a hash function based on a compression function, which consists of reinforcing by taking a method of resisting a current differential code analysis and the like as the principal method, also considering about some other attacks, such as a second preimage attack, further adding an input variable in the input of the final group of the compression function.

Abstract: The invention belongs to the field of information safety, in particular to the cryptology field, and relates to a method for reinforcing a hash function based on a compression function. The method is used for reinforcing key loops of the hash function, namely reinforcing a first group of the compression function and a final group of the compression function, and increasing the operations of multiple bits or utilizing a present safety group code algorithm by aiming at a majority of operations of a present hash function based on a single bit. The method comprises the following steps of: reinforcing by taking a method of resisting a current differential code analysis and the like as the principal method, also considering about some other attacks, such as a second preimage attack, further adding an input variable in the input of the final group of the compression function, namely a simple compression manner of all group information. The reinforcing method disclosed by the invention has the advantages that when key groups are reinforced, the increase of calculated amount is not large along with the increase of the length of a plaintext; and the decoding obstacle is configured through the most key position, the preimage attack, collision attack, the second preimage attack and the like can be effectively resisted.