中文摘要：

由于医疗数据和病人身份的敏感性,要求同时保证病人的医疗数据安全和身份信息不被泄露。现有方案满足匿名性要求,但拥有互补属性的用户可以合谋、且密文长度过长。针对上述问题,提出一种基于属性的抗合谋攻击的短密文环签密方案。该方案采用基于属性的环签密,保护了共享数据的机密性且隐藏用户的真实身份。其安全性可规约为CDH困难问题和DBDH困难问题。性能分析结果表明,与传统环签密方案相比,该方案能够抵抗合谋攻击且密文较短,具有更高的安全性和实现效率。

英文摘要：

Due to the sensitivity of medical data and the identity of the patient,it is required to ensure the security of the patient’s medical, and ensure the patient’s identity information is not leak. Existing schemes meet requirements,but the users with the complementary attributes can conspire and the ciphertext is long. In order to solve these problems,a new attribute-based and short ciphertextring signcryption scheme is presented,the scheme uses attribute-based ring signcryption,which protects the confidentiality of sharing data and conceals user’real identity,which security is proven equivalent to the CDH and DBDH problems. Performance analysis results show that, compared with existing schemes,the new scheme is able to resist conspiracy attacks and the ciphertext is short, so it has higher security and efficiency.