云计算里的一种无双线性对的模糊关键字加密方式

摘要

Already there has been many keyword searchable encryption researches done, but they mostly bear a weakness of oflfine keyword guessing attack, besides they are based on the heavier pairing computation. What’s more, most public encryption keyword search schemes can’t support fuzzy keyword search, this obvious drawback reduces the usability of the search system. The scheme we propose use the server’s public key to encrypt the keywords and data, and if outside attackers have no server’s private key, he will not obtain any information of the keyword ciphertexts, so we can use public channel to transport PEKS. The scheme not only supports accurate keyword search encryption but also supports the search when the keywords input have any spelling mistakes or format inconsistent situations. So it has greatly improved the availability of the system. The scheme use El Gamal encryption instead of the bilinear-pairing encryption, which greatly reduce the computational overhead.%现在已经有很多有效的搜索加密方案，但绝大多数方案都会受到离线关键字猜测攻击，而且他们都是基于双线性对的加密，开销很大。另外，大多数的公钥加密搜索方案都不支持模糊关键字的搜索，使得系统的可用性降低。因此文章提出了一个无双线性对的模糊关键字加密方案。在该方案中，采用服务器的公钥来加密关键字和数据，如果外部攻击者没有服务器的密钥，他将不能从关键字密文中获得任何有用信息，所以可以用公共信道来传输陷门。方案不仅支持精确关键字，当输入的关键字存在格式上偏差，或者拼写上的错误时，也支持搜索。方案使用El Gamal加密方式来代替双线性对的加密方式，这样大大减小了计算开销。