云环境下个人医疗信息的密文检索方法研究

CIPHERTEXT RETRIEVAL METHOD OF PERSONAL MEDICAL INFORMATION IN CLOUD ENVIRONMENT

针对云环境下个人医疗信息检索时出现的隐私问题,设计一种带有身份认证的公钥密文检索方法。采用RSA加密算法与SHA哈希算法对检索的关键词进行加密,先利用SHA对不同的关键词生成hash值,以防止检索时将关键词暴露给云服务器,接着用RSA公钥对关键词的hash值进行加密,并保存关键词密文。用户检索时,先用自己的私钥对采用相同SHA哈希算法生成的关键词hash值加密,同时加入用私钥对身份加密的数字签名信息,并一起上传云服务器。服务器检索时,利用用户的公钥进行解密,得到身份验证和关键词hash值。服务器先对身份进行认证,认证通过后再用公钥对关键词hash值加密,然后与保存的关键词密文进行匹配,相同则返回密文数据,不同则提示查询出错。此外对个人医疗数据的其他字段采用DES与RSA的混合加密方式。该方法不仅保障了系统的性能,而且有效地保护了用户数据的机密性与隐私性。

Aiming at the privacy problem of personal medical information retrieval in cloud environment,this paper designs a method of public key ciphertext retrieval with identity authentication. The RSA encryption algorithm and the SHA hash algorithm are used to encrypt the search keywords. SHA is used to generate hash values for different keywords to prevent the keywords from being exposed to the cloud server,and then use the RSA public key to encrypt the hash value of the keyword and save the keyword ciphertext. When the user retrieves,he encrypts the keyword hash with the same SHA hash algorithm with his own private key. At the same time,it adds a private key to the identity of the encrypted digital signature information,and uploads the cloud server. When the server retrieves,we use the user ＇s public key to decrypt and get authentication and keyword hash. The server first authenticates the identity,until the authentication passes,and we encrypt the keyword hash with the public key. Then we match the keyword with the saved ciphertext,the same is returned cipher text data,and different suggested that the query error. In addition,the other fields of personal medical data,we use DES and RSA mixed encryption. This method not only ensures the performance of the system,but also effectively protects the confidentiality and privacy of user data.