The Design And Implementation Of An Anonymous Security Trading System Based On The Space-Time Map

With the popularization of the Internet and online transaction, the needs of protecting the transaction security and anonymity rise gradually. The demand becomes more urgent for the people who want to report news clues and evidence or other sensitive information online. Traders want to ensure the safety of transaction, at the same time, realize the anonymity during the trading to benefit from the transaction and avoid the trade’s impact frequently.In this thesis, we map the anonymous transactions scene in the real world to the network, design and realize an anonymous security trading system based on the space-time map. The main research work of this thesis is as follows:(1) Set up a website that can only enter through the anonymous communication system Tor. User must enter the site by using this system in order to protect the anonymity of the user.(2) Set up an anonymous information security transaction mechanism. Users enter the chat room by using a fake name that no related with the real identity, to realize the anonymity of users. At the same time, all the transaction information is encrypted, to ensure the anonymity and confidentiality in the process of negotiation.(3) Establish a key escrow system. The system escrow the user key and send the hosting credentials to user. The user shows the credentials to certify his key has already hosted, to avoiding trading losses caused by a single default hosting server. The system realize segmentation and escrow of the user key and introduced the threshold mechanism, to avoid the leakage of user information caused by the failure of part hosting servers. At the same time, introduced the Kerberos authentication technology, users could make bidirectional authentication with key hosting servers. Only the user with deal authority could make deal in the system. The mechanism enhance system security by user’s authentication and ensure the safety of user’s transaction.(4) Introduced the time and location information as a password of trade negotiation, and on this basis, generate the key. Because of the time and location information is easy to remember and could not exhaustive (computing security), not only reduce the difficulty of memory, but also enhance the security of the system.