Access Control for Distributed Ledgers in the Internet of Things: A Networking Approach
In the Internet of Things (IoT) domain, devices need a platform to transact
seamlessly without a trusted intermediary. Although Distributed Ledger
Technologies (DLTs) could provide such a platform, blockchains, such as
Bitcoin, were not designed with IoT networks in mind, hence are often
unsuitable for such applications: they offer poor transaction throughput and
confirmation times, put stress on constrained computing and storage resources,
and require high transaction fees. In this work, we consider a class of
IoT-friendly DLTs based on directed acyclic graphs, rather than a blockchain,
and with a reputation system in the place of Proof of Work (PoW). However,
without PoW, implementation of these DLTs requires an access control algorithm
to manage the rate at which nodes can add new transactions to the ledger. We
model the access control problem and present an algorithm that is fair,
efficient and secure. Our algorithm represents a new design paradigm for DLTs
in which concepts from networking are applied to the DLT setting for the first
time. For example, our algorithm uses distributed rate setting which is similar
in nature to transmission control used in the Internet. However, our solution
features novel adaptations to cope with the adversarial environment of DLTs in
which no individual agent can be trusted. Our algorithm guarantees utilisation
of resources, consistency, fairness, and resilience against attackers. All of
this is achieved efficiently and with regard for the limitations of IoT
devices. We perform extensive simulations to validate these claims.
Authors
Andrew Cullen, Pietro Ferraro, William Sanders, Luigi Vigneri, Robert Shorten