灵活访问且模糊可搜索的EHR云服务系统

Flexibly Accessed and Vaguely Searchable EHR Cloud Service System

在电子健康记录系统(E-Healthcare Record Systems,EHRS)中,一些方案利用密钥策略ABE(KP-ABE)来保护隐私。由用户指定一个访问策略,密文只有与访问策略相匹配时才能被解密。现有的KP-ABE要求在生成密钥期间必须先确定访问策略,这在EHRS中是不可行的,因为有时访问策略在密钥生成后才被决定。基于KP-ABE,提出一种灵活访问且模糊可搜索的EHR云服务系统。该系统不仅实现了基于关键字容错的云端密文搜索,而且允许用户重新定义访问策略并为之生成密钥,因此一个精确的访问策略将不再是必需的。最后,证明了该方案的安全性。

In e-healthcare record systems(EHRS),some schemes exploit key-policy ABE(KP-ABE)to protect privacy.An access policy is specified by the user,and the ciphertexts can be decrypted only when they match users’access plicy.The existing KP-ABE requires that the access policies should be confirmed first during key generation,which is not always practicable in EHRS,because the policies are sometimes confirmed after key generation.Based on KP-ABE,this paper proposed a flexibly accessed and vaguely searchable EHR cloud service system.This system not only fulfills the cloud ciphertext search based on keyword fault-tolerant technique,but also allows users to redefine their access policies and generates keys for the redefined ones,hence,a precise policy is no longer necessary.Finally,the scheme was proved to be secure.