  With the support of cloud computing, large quantities of data collected from
various WSN applications can be managed efficiently. However, maintaining data
security and efficiency of data processing in cloud-WSN (C-WSN) are important
and challenging issues. In this paper, we present an efficient data outsourcing
scheme based on CP-ABE, which can not only guarantee secure data access, but
also reduce overall data processing time. In our proposed scheme, a large file
is divided into several data blocks by data owner (DO) firstly. Then, the data
blocks are encrypted and transferred to the cloud server in parallel. For data
receiver (DR), data decryption and data transmission is also processed in
parallel. In addition, data integrity can be checked by DR without any master
key components. The security analysis shows that the proposed scheme can meet
the security requirement of C-WSN. By performance evaluation, it shows that our
scheme can dramatically improve data processing efficiency compared to the
traditional CP-ABE method.
