改进的国际数据加密算法的子密钥扩展算法

摘要

This paper improves the subkey extendable algorithm of International Data Encryption algorithm(IDEA).This algorithm employs the pseudo-random sequence to implement the randomness of the subkey.So the attacker can not analyze the position of the initial key in subkeys,and the attacker can not ensure the position of the weak key.In the process of subkey generation using pseudo-random sequence,the linear probing rescattering is imported to avoid the occurrence that different frequencies of initial key may cause new weak key.Testable attacking experiment and analysis of security and efficiency show that such improvement can enhance the safety and efficiency.%提出了一种改进的国际数据加密算法（International data encryption algorithm,IDE-A）子密钥扩展算法。该算法采用伪随机序列产生具有无序性的子密钥,令攻击者无法有效地分析子密钥中初始密钥位的位置,也无法确定弱密钥的位置。无序的子密钥破坏了针对性攻击的攻击条件,使这些攻击无效。在只有伪随机序列产生的子密钥中,对初始密钥使用频率的不同会导致新弱密钥类的产生,因此引入线性探测再散列来防止该现象的发生。对该算法进行的验证性攻击实验及安全性、效率性分析都表明该算法是安全高效的。