Secure Keyword Search and Data Sharing Mechanism for Cloud Computing

Abstract

The emergence of cloud infrastructure has significantly reduced the costs of hardware and 
software resources in computing infrastructure. To ensure security, the data is usually 
encrypted before it's outsourced to the cloud. Unlike searching and sharing the plain data, it is 
challenging to search and share the data after encryption. Nevertheless, it is a critical task for 
the cloud service provider as the users expect the cloud to conduct a quick search and return 
the result without losing data confidentiality. To overcome these problems, we propose a 
ciphertext-policy attribute-based mechanism with keyword search and data sharing (CPAB
KSDS) for encrypted cloud data. The proposed solution not only supports attribute-based 
keyword search but also enables attribute-based data sharing at the same time, which is in 
contrast to the existing solutions that only support either one of two features. Additionally, the 
keyword in our scheme can be updated during the sharing phase without interacting with the 
PKG. In this paper, we describe the notion of CPAB-KSDS as well as its security model. 
Besides, we propose a concrete scheme and prove that it is against chosen ciphertext attack and 
chosen keyword attack secure in the random oracle model. Finally, the proposed construction 
is demonstrated practical and efficient in the performance and property comparison.