中文摘要：

作为云环境的重要构成部分，虚拟机的身份管理与认证是云计算安全中的重要问题.由于云计算环境具有大规模、分布式等特点，通常在云内存在多个身份权威.而现有的虚拟机身份证明方案中，身份权威的信息是公开的，因此在应用于云计算环境时，将造成组织结构、虚拟机位置等相关性信息的泄露，与云环境的结构透明、位置无关等特性相违背.提出的虚拟机身份证明，在保障原有认证性和信任关系的情况下，实现了身份证明过程中对身份权威信息的隐藏，避免了上述组织结构、位置等信息的暴露，可支持云环境结构透明、位置无关的特点.此外，该方案实现了对平台属性的安全证明，且证明过程无需身份权威的参与，避免了校验者和身份权威的合谋攻击，进一步提高了方案的安全性和实用性.

英文摘要：

Being a vital constituent of cloud environment, the identity management and authentication of the system virtual machine is of great importance to cloud computing security. Multiple identity authorities exist in the large-scale, wide-distributed cloud environment and information regarding the authorities is publicly exposed in the current identity management and authentication scheme. Such deficiency of the scheme in the application of cloud environment poses the danger of revealing the organization and location of the users＇ platforms, violating the nature of cloud environment, i.e. organization transparency and location i.e. This paper presents the issuer-anonymous attestation scheme which, without altering the level of authentication and creditability, protects the anonymity of the platforms and the privacy of the issuers in the process of identity certification, effectively preventing information revelation in accordance with the transparency and independence nature of cloud environment. Furthermore, the proposed scheme realizes the attestation of the attributes of the platforms independently, requiring no participation of the identity authorities, and therefore, excludes the possibility of conspiracy attack between the inspector and the identity authorities and enhances the practicability and security of the scheme.