Biblio

Many blockchain transactions require blockchain-external data sources to provide data. Oracle systems have been proposed as a link between blockchains and blockchain-external resources. However, these Oracle systems vary greatly in assumptions and applicability and each system addresses the challenge of data on-chaining partly. We argue that Data On-chaining must be done in a trustworthy manner and, as a first contribution, define a set of key requirements for Trustworthy Data On-chaining. Further, we provide an in-depth assessment and comparison of state-of-the-art Oracle systems with regards to these requirements. This differentiation pinpoints the need for a uniform understanding of and directions for future research on Trustworthy Data On-chaining.

The Blockchain is an emerging paradigm that could solve security and trust issues for Internet of Things (IoT) platforms. We recently introduced in an IETF draft (“Blockchain Transaction Protocol for Constraint Nodes”) the BIoT paradigm, whose main idea is to insert sensor data in blockchain transactions. Because objects are not logically connected to blockchain platforms, controller entities forward all information needed for transaction forgery. Never less in order to generate cryptographic signatures, object needs some trusted computing resources. In previous papers we proposed the Four-Quater Architecture integrating general purpose unit (GPU), radio SoC, sensors/actuators and secure elements including TLS/DTLS stacks. These secure microcontrollers also manage crypto libraries required for blockchain operation. The BIoT concept has four main benefits: publication/duplication of sensors data in public and distributed ledgers, time stamping by the blockchain infrastructure, data authentication, and non repudiation.