Research Of The Access Control Techniques Based On Platform Integrity Attestation

Information networks are evolving rapidly while the security problem is becoming more and more serious. Among all kinds of security threats, Botnet is emerging obviously these years. As reported by the CNCERT, there had been 837 thousand of IP addresses controlled by Botnet in China in 2009. The amount is just like a corner of iceberg floating on the surface, there must be far more controlled bots hidden underground.The vulnerability of user endpoints is one of the main reasons leveraging the spread of Botnet and because of which the endpoint security management has became a hotspot among various security technologies. The endpoint access control technology researched in this paper is one vital component of endpoint security management solution. The basic idea of access control is that the server decide whether the endpoints could be authorized to access to the network based on the evaluation of the security status collected from the endpoints such as anti-virus software installation, OS patches installation and so on.One of the security status which is called Platform Integrity is emerging as a necessary attestation in some scenarios. Platform integrity means that the hardware or software of the platform are not modified so that it can prevent attackers to hack the system from the root. Applying this mechanism to real networks has been leveraged by the development of trusted computing technologies. The research of this paper focus on the access control technology based on platform integrity attestation and it can be divided into three aspects of work:1. Research on trusted environment(TrE) in telecommunication deviceThe TrE is mainly used to guarantee the authenticity and integrity of the platform integrity information which should be sent to the server for validation. Detailed research is described as the following:Proposed a logical architecture of TrE suitable for telecommunication devices. According to the technical requirement of TrE proposed by 3GPP relative standard, this paper proposed a lightweight trusted platform architecture based on TCG trusted model and concept. The proposed architecture can fit the technical requirement of secure storage, secure boot and remote platform integrity attestation.Analyzed the TrE implementation based on TPM and TrustZone technologies. Did research on TrE physical implementation on SoC(System on Chip) built in Home Base Station and did brief analysis on security and feasibility.2. Research on remote platform attestation protocolsThe platform integrity information needs to be sent to the server through proper protocols. The process contains authentication schema and detailed message content. Adaptation of current protocols to encapsulate the platform integrity is also needed.Proposed a security enhanced remote platform integrity attestation schema. This paper analyzed the MiTM(Man in The Middle) security problem of current remote integrity attestation protocol(TLS-Attestation). Since the SSL/TLS handshake protocol is independent from platform integrity attestation information, it is possible for attackers to make a MiTM. This paper proposed an security enhanced attestation schema to integrate the remote platform integrity attestation protocol and the SSL/TLS handshake protocol through TPM_Quote operation.Designed remote platform integrity attestation protocol suitable for telecommunication device. This paper introduces security threats of home base station in LTE scenario and describes the requirement of platform integrity attestation. The protocol design covers integrity measurement content and integrity information transmission. Part of the protocol design has been adopted by TCG organization as a future program called "IF-M for Telecom".3. Research on device collaboration for access controlThe network side can get more informative real-time status of endpoints and a more flexible control schema through collaboration. This paper describes several typical current mechanisms of security device collaboration and summarizes the collaboration models. And then a role-based security collaboration framework is introduced to classify the security devices into sensors, analyzers and executors. Based on the framework, a Two-Tiered policy mechanism is proposed to improve collaboration effect between sensors and executors. This part of work has been adopted by CCSA(China Communication Standard Association) as a research report.