The Preneel-Lai’s open problem concerns that is it possible to construct 2m-bit DM hash scheme based on the m-bit DM hash scheme so that the security can also be improved. This paper presents a constructive method to...The Preneel-Lai’s open problem concerns that is it possible to construct 2m-bit DM hash scheme based on the m-bit DM hash scheme so that the security can also be improved. This paper presents a constructive method to show that this problem can be solved. Two 2m-bit DM hash schemes has been constructed with hash rate being 1 and 1/2 respectively. Security analysis shows that both of them have computational complexities of \%O(2\+\{m+1\})\% against free-start target attack and meet in the middle attack alike, thus both more secure.展开更多
文摘The Preneel-Lai’s open problem concerns that is it possible to construct 2m-bit DM hash scheme based on the m-bit DM hash scheme so that the security can also be improved. This paper presents a constructive method to show that this problem can be solved. Two 2m-bit DM hash schemes has been constructed with hash rate being 1 and 1/2 respectively. Security analysis shows that both of them have computational complexities of \%O(2\+\{m+1\})\% against free-start target attack and meet in the middle attack alike, thus both more secure.
