Multi-layer Attestation for Internet of Things using Blockchain

Internet of Things (IOT) by its nature comprises of heterogeneous devices with varying degree of resources and capabilities with common attributes that those are connected and uniquely identifiable over the network. Given the always on always connected nature of IoT devices along with virtually limitless applications, the attack surface of constituent IoT device is very large. Hence ability to attest IoT devices for its trustworthiness is very important factor in determining trustworthiness of IoT network. In past significant amount of research has focused on possible attestation mechanisms for IoT but all those proposals invariably depend on specific hardware implementation like TrustZone, SGX, TPM, RTC, memory with OTP etc. Sine all such security primitives are either architecture or manufacturer specific it is not possible to build common unified attestation scheme for all constituent IoT devices in a typical IoT network using any of those primitives. This research work proposes different pragmatic approach to define such common and scalable attestation scheme that all IoT devices within IoT network could deploy. The proposed scheme makes use of memory management which is one of most basic features of any processor or controller to build common and scalable attestation mechanism for all types of IoT devices. The approach is to understand threat model and then develop mitigations in pragmatic manner.