Keyword Searchable Encryption with Fine-Grained Forward Secrecy for Internet of Thing Data.

With the incessant development and popularization of Internet of things (IoT), the amount of the data collected by IoT devices has rapidly increased. This introduces the concerns over the heavy storage overhead to such systems. In order to relief the storage burden, a popular method is to use the outsourced cloud technology. While the massive collected IoT data is outsourced to the cloud, the security and privacy of these outsourced data is therefore of critical importance, and many researches have been done in this area. In this paper, we propose a new keyword searchable encryption system with fine-grained right revocation. In the system, each IoT device’s data are stored in a special document. Thus the data owner can revoke users’ search rights at fine-grained document level by setting new random number in each time period. Especially, to realize search right revocation, re-encryption operations on keyword cipheretexts are not needed in our scheme. Then, we instantiate a valid construction in practical application and discuss the security properties in the construction. Our performance evaluations show that the proposed construction is efficient.