Anonymous Communication Based On Trusted Hardware SGX

With the advent of big data,there are many data analysis methods such as classification,clustering,similarity matching,and prediction.Common data that does not involve sensitive information may also lead to serious information disclosure.In order to ensure the privacy of the communication system,it is not enough to simply protect the content of the message.The anonymous communication system is different from the traditional communication system.In addition to protecting the content of the message,the anonymous communication system is also committed to protecting the metadata of both parties.The security requirements of anonymous communication systems can be summarized into the following three aspects: 1)Security of message content.2)Security of the sender's identity.3)Security of the recipient's identity.The existing anonymous communication system can only satisfy a small number of users while ensuring anonymity,and an anonymous communication system capable of providing services for multiple users often cannot achieve anonymity.In the background of the above research,it is necessary to improve the communication efficiency and reduce the communication cost while ensuring the anonymity of the anonymous communication system.Our main work in this paper is stated as follows:(1)First proposed a basic framework of anonymous communication.The framework uses a non-interactive communication model and an anonymous identity-based encryption scheme that protects against traffic analysis attacks and improves communication efficiency partly.However,through the analysis of the security and efficiency for the framework,the existence of trusted third-party PKG in the framework seriously affects the security of the framework.On the other hand,the method designed to receive messages is too straightforward.The method of forcing the user to decrypt all the message ciphertext consumes a lot of bandwidth of the network and increases the computing burden of the user.(2)According to the problems based on the basic framework of anonymous communication from(1),this paper combines the private information retrieval technology based on the additional homomorphic with the trusted hardware SGX in the fourth chapter to improve framework of anonymous communication from(1).Firstly,the private information retrieval technology is used to hide the reading mode of the message ciphertext.After the reading is completed,the isolation of the trusted hard SGX is used to provide a secure transmission channel for the message ciphertext.The user can accurately obtain the message ciphertext belongs to him,without unnecessary decryption calculation,thereby further improving communication efficiency.In addition,the cloud platform uses the SGX instruction set to create a secure area instead of the PKG in(1)to generate a private key for the user,and the user platform also creates a secure area to receive the private key.The process of making the private key from the generation to the distribution is always in a safe execution environment,which improves the security of the anonymous communication framework.(3)According to the SGX related configuration file released by the official website of Intel,we built an experimental environment and tested the memory protection mechanism of SGX to verify the security of the trusted zone provided by SGX.The PBC library developed by Stanford University is used to implement the encryption and decryption process,calculat the decryption time,and verify the better efficiency of the SGX-based anonymous communication scheme.