A TBOI (Time-Based Operation Interruption) Protocol to Prevent Late Information Flow in the IoT

Abstract

In the IoT (Internet of Things), devices have to be prevented from maliciously accessed. The CapBAC (Capability-Based Access Control) model is proposed to make IoT devices secure. In the CapBAC model, an owner of a device issues a capability token, i.e. a set of access rights to a subject. Here, the subject is allowed to manipulate the device according to the access rights authorized in the capability token. Suppose a subject \(sb_i\) is allowed to get data from a device \(d_2\) but not allowed to get data from a device \(d_1\). The subject \(sb_i\) can get the data of the device \(d_1\) in the device \(d_2\) after another subject \(sb_j\) brings the data from the device \(d_1\) to the device \(d_2\). Here, the data in the device \(d_1\) illegally flow to the subject \(sb_i\). In order to prevent illegal information flow, an OI (Operation Interruption) protocol is proposed in our previous studies, where illegal get operations are interrupted. However, in the OI protocol, a subject \(sb_i\) can get data \(dt_1\) of a device \(d_1\) generated at time \(\tau \) even if the subject \(sb_i\) is not allowed to get the data \(dt_1\) at time \(\tau \). In this case, the data \(dt_1\) come to the subject \(sb_i\) later than expected by the subject \(sb_i\) to get the data \(dt_1\), i.e. the data \(dt_1\) flow late to the subject \(sb_i\). In this paper, we newly propose a TBOI (Time-Based OI) protocol to prevent late information flow in addition to illegal information flow from occurring.