CAJ | 학술논문

云存储具有高可扩展性、低成本等特点，为用户文件共享提供了经济高效的服务，同时也带来了新的安全问题：在不可信的云存储中，如何在保证文件的安全和隐私的前提下，为特定用户共享。该方案提出了基于身份的公钥密码体制基础上，运用高效安全的代理环签名、动态广播加密和双线性对技术，通过授权用户列表，能动态加入和撤销共享用户，不需要更改老用户相关密钥。该方案简单可行，具有可追溯性、匿名性、不可伪造性等特点。
운존저구유고가확전성、저성본등특점，위용호문건공향제공료경제고효적복무，동시야대래료신적안전문제：재불가신적운존저중，여하재보증문건적안전화은사적전제하，위특정용호공향。해방안제출료기우신빈적공약밀마체제기출상，운용고효안전적대리배첨명、동태엄파가밀화쌍선성대기술，통과수권용호렬표，능동태가입화철소공향용호，불수요경개로용호상관밀약。해방안간단가행，구유가추소성、닉명성、불가위조성등특점。
Cloud storage, characterized by high extensibility and low cost, offers users the economical and efficient service of file sharing, and in the meantime brings about a new secure problem, that is, how files in the undependable cloud storage are shared by specific users on precondition that their security and privacy are guaranteed. On the basis of identity-based cryptography, the scheme applies proxy ring signature, dynamic broadcast encryption, and bilinear pairings, which are efficient and safe. Through authorized us-er list, it can add and remove the sharing user without changing old users’ secrete key. The scheme is easy, feasible, traceable, anon-ymous and unable to fake.