Rechained: Sybil-Resistant Distributed Identities for the Internet of Things and Mobile Ad Hoc Networks

Abstract

Today, increasing Internet of Things devices are deployed, and the field of applications for decentralized, self-organizing networks keeps growing. The growth also makes these systems more attractive to attackers. Sybil attacks are a common issue, especially in decentralized networks and networks that are deployed in scenarios with irregular or unreliable Internet connectivity. The lack of a central authority that can be contacted at any time allows attackers to introduce arbitrary amounts of nodes into the network and manipulate its behavior according to the attacker’s goals, by posing as a majority participant. Depending on the structure of the network, employing Sybil node detection schemes may be difficult, and low powered Internet of Things devices are usually unable to perform impactful amounts of work for proof-of-work based schemes. In this paper, we present Rechained, a scheme that monetarily disincentivizes the creation of Sybil identities for networks that can operate with intermittent or no Internet connectivity. We introduce a new revocation mechanism for identities, tie them into the concepts of self-sovereign identities, and decentralized identifiers. Case-studies are used to discuss upper- and lower-bounds for the costs of Sybil identities and, therefore, the provided security level. Furthermore, we formalize the protocol using Colored Petri Nets to analyze its correctness and suitability. Proof-of-concept implementations are used to evaluate the performance of our scheme on low powered hardware as it might be found in Internet of Things applications.

Formalizing the Blockchain-Based BlockVoke Protocol for Fast Certificate Revocation Using Colored Petri Nets

“…Leiding et al [19,20] first formalized the Authcoin protocol [21] using CPNs and subsequently performed a risk and threat analysis using the ISSRM domain model [22] before mitigating identified risks using security risk-oriented patterns (SRPs) [23,24]. Finally, Bochem and Leiding [36] used CPNs to verify various properties of the blockchain-based Rechained protocol formally.…”

“…CPN-ML is an expression programming language for inscriptions which are used to further specify data types and operations of the modeled system. CPN tokens and their colors represent the different data types of the modeled system" [36].…”

“…Furthermore, CPNs use CPN-ML expressions to specify and implement data types and operations of the modeled system, which correspond to the functionalities of smart contracts in the context of blockchain technology. Finally, the hierarchical structure of CPN models can be used to formalize blockchain-based dApps (decentralized applications) components of interleaved smart contracts" [36].…”

“…Finally, goals are further decomposed into multi-layered sub-goals until the lowest atomic level is reached. Additionally, roles and quality goals may be assigned to goals and are inherited to lower-level goals" [36]. The top-level goal model of BlockVoke is shown in Figure 5, while the complete goal model of BlockVoke with all refinements is available in Appendix A.…”

Secure Localization in Wireless Sensor Networks

“…Chapter 3 cites the paper titled "Rechained: Sybil-Resistant Distributed Identities for the Internet of Things and Mobile Ad hoc Networks" by Arne Bochem and Benjamin Leiding of the Institute of Computer Science, Telematics Group, University of Goettingen, Germany (e-mail: {bochem,benjamin.leiding}@informatik.uni-goettingen.de) [20] verbatim, except for formatting and handling of acronyms and Section 3.8. It was published in the open-access MDPI Sensors journal under the Creative Commons CC BY 4.0 license, permitting use in this thesis, as long as attribution, such as this, is provided.…”