中文摘要：

认证加密算法能同时提供信息的加解密及完整性检验两个功能,它已被广泛应用于各种网络安全系统中。最近伴随着欧洲CAESAR密码算法的征集活动,认证加密算法倍受业界关注。SCREAM算法凭借其新颖的设计理念和算法结构,已经顺利入围CAESAR竞选中的第二轮候选算法。而该算法是否存在新的安全性问题是目前的研究热点之一。基于SCREAM参数的变化特点,利用累加值碰撞的思想提出了一种新的伪造攻击。研究结果表明,新攻击成功的概率为1,所需的时间复杂度及数据复杂度均可忽略;此外该攻击同样适用于SCREAM的一种变体算法,即i SCREAM。与已有的攻击相比较,新攻击所需的复杂度更低,攻击范围更灵活有效。

英文摘要：

Authentication encryption algorithms have been widely used in networks security system since these algorithms can efficiently provide both privacy and integrity measurement for data transmission. Recently, authentica- tion encryption algorithms have received attentions extensively since the event of CAESAR cipher solicitation was developed. SCREAM had been selected as one of the second-round candidates in CAESAR competition because of its novel structure and design idea. Currently, the security issue of SCREAM becomes an interesting research topic. Based on the characteristic of SCREAM variable parameters, a new forgery attack was proposed by using the basic idea of the sum collision. In particular, this attack could also be used to iSCREAM algorithm. Different to the best known attacks, the new attack requires less time and data complexities. It is shown that this new attack is more flexible and effective. Furthermore, the success probability of the forgery will be one.