| With the rapid development of network and information acquisition equipment, tremendousopportunities for cooperative computation have been opened up in the word of Internet of Things.Therefore, it is easy to collect the private data from users through the applications based oncollaborative computing, and privacy concerns become an increasingly critical issue, recently.Secure multi-party computation plays an important role in privacy-preserving. It also works inPrivacy-Preserving computational geometry and data mining. In this thesis, we devote to investigatethe solutions to some secure two-party problems in a cooperative environment.The scalar (dot) product is one of the most used sub-protocol in SMC. Although severalsolutions exist in the relevant literature for this problem, the need for more efficient and morepractical solutions still remains. In this thesis, a very efficient and very practical secure scalarproduct protocol is presented. To show that our protocol is much more efficient than the existingones, it is compared to the most common scalar product protocols. Another problem iscollaboratively computing the Euclid-distance between two private vectors without disclosing theprivate input to each other. The secure scalar product protocol proposed above is used as a buildingblock in the secure distance protocol. Besides, a general privacy-preserving Euclid-distanceprotocol with untrusted third party and high secrecy is presented based on the extension of thescalar product proposed by W. L. Du. A privacy-preserving distance measurement solution withhigh efficiency is the third distance protocol presented in this thesis. And all of them proved to besecure and efficient in the comparison with the previous methods in some fields. Range searchingproblem has been little invested since it was first proposed by Atallah. Two protocols of rangesearching for different secure needs are proposed base on the permutation algorithm in this thesis.This thesis also presents the design and implementation of a privacy-preserving oriented locationbased service prototype system in Internet of Things. One of the above rang searching algorithm isimplemented on the prototype system, and verified feasible and effective. |
