The collision of one keyed Hash function based on chaotic map and analysis
一种基于混沌的带密钥Hash函数的碰撞问题及分析

The collision of a keyed hash function based on chaotic map is pointed out. Its principle is analyzed in theory. The definition of the nonsingularity is presented based on analyzing digital discrete chaotic sequence. The necessary and sufficient conditions for the nonsingularity is deduced. The period of digital discrete chaotic sequence with variable parameter is discussed. The result shows that the singulartiy of chaotic sequence leads to the collision of the hash function. So the digital method of chaotic map must be chosen carefully to ensure the nonsingularity of chaotic sequence.