基于密文的中文关键词模糊搜索方案

Chinese Keyword Fuzzy Search over Encrypted Cloud Data

随着越来越多的人将数据和信息存储在云服务器上,其在给人们带来便捷服务的同时,其安全性和可靠性也越来越得到人们的关注。由于基于密文的搜索特殊性,衍生出了可搜索加密的研究。针对目前尚缺少支持中文关键词的可搜索加密方案,文章提出了一种在安全云存储环境下支持中文关键词模糊搜索的方案。目前可搜索加密方案解决了密文环境下英文关键词的安全快速模糊搜索问题。由于中文的特殊性,若按英文关键词的处理方式,把任意两个中文间的差异都用一个编辑距离来表示,则增加了模糊匹配过程中的模糊程度,所以现有方案不适用于基于密文的中文关键词模糊搜索。文章使用基于拼音的汉字串相似度衡量方法,提出了基于Grams的中文关键词模糊集构造算法(Chinese-Gram-based),改进了现有的搜索索引结构,提出了基于n叉树的关键词陷门搜索索引结构,提高了云服务器搜索效率。安全分析表明,该方案满足用户数据保密性和查询请求隐私性。实验说明该方案的可行性以及中文关键词模糊搜索的高效性。

With more and more people put the data and information on the cloud servers, people are increasingly putting more and more attention on the safety and reliability while they enjoy the convenient services. Due to the special nature of ciphertext, research on searchable encryption is produced. For the lack of Chinese keyword search in searchable encryption, Chinese keyword fuzzy search scheme is proposed in this paper. Currently searchable encryption schemes solve the English keyword secure and fast fuzzy search in ciphertext environment. Due to the special nature of Chinese keyword, If an edit distance is used to represent the difference between any two Chinese keywords in the sane way on the English keyword, it will increase the degree of fuzzy in matching process. so the existing program does not apply to Chinese keywords search in ciphertext environment. Basing on the use of Pinyin-based edit distance to measure the similarity of chinese character string, a Chinese-Gram-based is proposed in this paper, improving the existing search index structure, proposing trapdoor search index based on the structure of n-ary tree and improving the search efficiency. Safety analysis shows that the scheme meets the user data confidentiality and privacy of queries, The experiment shows the efficiency of the search feasibility and efficiency of the program in Chinese keyword fuzzy search technology.