Access Control for Distributed Ledgers in the Internet of Things: A Networking Approach

Abstract

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.

Improving Quality of Service for Users of DAG-based Distributed Ledgers

“…While our results generally apply to any DAG-based DLT, we include some details of IOTA's implementation as a concrete example. Specifically, the rate at which nodes can issue transactions in the IOTA network is regulated by an access control algorithm [27], [28]. Each node regulates its own issue rate via a distributed algorithm based on the additive increase multiplicative decrease (AIMD) algorithm [29]- [31] 3 .…”

“…In a PoW ledger, this would be a fixed value, λi (t) = λ i , based on the computing power of node i (provided the node's computing power remains constant). In this work, however, we focus our attention on the IOTA protocol in which the service rate of the LTP is governed by an AIMD rate setter [27] as part of IOTA's access control algorithm which replaces the need for PoW. We employ a max-min moving average filter to estimate the issue rate of each node as described in the Appendix.…”

“…Transactions issued by nodes need to be forwarded to neighbours to achieve a shared view of the ledger. As described in [27], the total rate at which nodes can process new transaction ν. In the below simulations, ν is set to 50 transactions per second.…”

Controlling Transaction Rate in Tangle Ledger: A Principal Agent Problem Approach

“…Their model assumes that the computational power of the agent is known to the transaction rate regulator. [18] borrows an idea from wireless networks to control the transaction using an access control scheme. Congestion control has also been studied in the context of wireless communication.…”

Protocol-Based and Hybrid Access Control for the IoT: Approaches and Research Opportunities

“…To this end, in the future, the distributed ledger technology, e.g., blockchain, can provide a solution [122,123]. Furthermore, it reinforces the decentralized requirement of access control in both IoT and IIoT systems at scale [124]. For instance, hybrid access control is proposed in [125] for IIoT networks.…”