一种CCA安全的高效公钥广播加密方案  

An Efficient CCA Secure Public Key Broadcast Encryption Scheme

作　　者：林慕清[1] 周杨[2] 李福祥[1] 周福才[2] 

机构地区：[1]东北大学信息科学与工程学院,沈阳110819 [2]东北大学软件学院,沈阳110819

出　　处：《小型微型计算机系统》2015年第1期116-120,共5页Journal of Chinese Computer Systems

基　　金：国家科技重大专项项目(2013ZX03002006)资助;辽宁省百千万人才工程项目(2011921071)资助;国家"八六三"高技术研究发展计划项目(2009AA01Z122)资助

摘　　要：广播加密是一种利用广播信道传输加密信息的方式,信息的发送者可以动态的指定接收者集合,并且只有属于接收者集合的用户才能够正确解密信息.目前已存在多种基于公钥的广播加密方案,但当用户的大子集和小子集同时存在时,已知的方案的效率均较低.本文在BGW2方案的基础上,提出了一个CCA安全的高效公钥广播加密方案,方案采用BDHE假设,在加密过程中通过共享广播加密方案的参数来同时对两种情况进行处理,提高了同时发送给大子集和小子集时的效率.安全性分析表明,方案可以抵抗选择密文攻击和集合外用户的共谋攻击.方案的密文和用户的私钥大小都是一个常量,但公钥的大小和用户数量线性相关.实验结果表明,相对于BGW2方案,本文方案的加解密算法的执行效率有很大的提高.A broadcast encryption is a cryptographic scheme that uses broadcast channel to transmit encrypted content. It ensures that only a subset of target users, which is dynamically selected at the time of encryption, can decrypt the content. There are many broadcast encryption schemes based on public key cryptography at present. However, the previous schemes have very low efficiency when the broadcaster needs to send message to both large and small subset simultaneously. In this paper, we present an efficient CCA secure public key broadcast encryption scheme using the BDHE assumption. The scheme is based on the BGW2 scheme, and improves the ef- ficiency of sending message to both large and small subset by sharing system parameters of broadcast encryption. Security analysis shows that the scheme can resist chosen ciphertext attack and collusion of the users outside the subset. Both ciphertext and private key are of constant size,but the public key size is linear in the total number of receivers. The experimental results show that, compare to BGW2 scheme,the efficiency of our scheme＇s encryption and decryption algorithm has been greatly improved..

关 键 词：广播加密 公钥加密 选择密文安全 抗共谋 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]