Biblio
Internet of Things (IoT) and cloud computing are promising technologies that change the way people communicate and live. As the data collected through IoT devices often involve users' private information and the cloud is not completely trusted, users' private data are usually encrypted before being uploaded to cloud for security purposes. Searchable encryption, allowing users to search over the encrypted data, extends data flexibility on the premise of security. In this paper, to achieve the accurate and efficient ciphertext searching, we present an efficient multi-keyword ranked searchable encryption scheme supporting ciphertext-policy attribute-based encryption (CP-ABE) test (MRSET). For efficiency, numeric hierarchy supporting ranked search is introduced to reduce the dimensions of vectors and matrices. For practicality, CP-ABE is improved to support access right test, so that only documents that the user can decrypt are returned. The security analysis shows that our proposed scheme is secure, and the experimental result demonstrates that our scheme is efficient.
How to debug large networks is always a challenging task. Software Defined Network (SDN) offers a centralized con- trol platform where operators can statically verify network policies, instead of checking configuration files device-by-device. While such a static verification is useful, it is still not enough: due to data plane faults, packets may not be forwarded according to control plane policies, resulting in network faults at runtime. To address this issue, we present VeriDP, a tool that can continuously monitor what we call control-data plane consistency, defined as the consistency between control plane policies and data plane forwarding behaviors. We prototype VeriDP with small modifications of both hardware and software SDN switches, and show that it can achieve a verification speed of 3 μs per packet, with a false negative rate as low as 0.1%, for the Stanford backbone and Internet2 topologies. In addition, when verification fails, VeriDP can localize faulty switches with a probability as high as 96% for fat tree topologies.