Access control is widely used technology for securing sensitive resources of information systems, such as personal data managed by cloud-based data store and sensitive data stream collected by smart devices. Existing access control systems mainly adopt centralized architecture and static access control models, including Access Control List, Role-based Access Control and Attribute-based Access Control. However, these systems fail to meet the increasing requirements of behavior based dynamic access control or requirements of owner initiated autonomous access control without relying on trustworthy third parties and suffer inherent drawbacks of single point of failure or dishonesty. To this end, a novel blockchain-based and provenance enabled dynamic access control scheme called BPDAC is proposed. Specifically, it collects and stores data provenance on blockchain to enable behavior-based dynamic access control; in particular, the quick lookup table structure is designed to speed up access control evaluation based on provenance with increasing complexity. It also provides specifications for formulating access control policies based on provenance. It utilizes a set of smart contracts on blockchain to enable decentralized and reliable autonomous access control. A prototype system is implemented on the Hyperledger Fabric and experiments are conducted to show that the proposed scheme is practically feasible and scalable in terms of the performance metrics of throughput and latency.
Aditya Pathak, Irfan Al‐Anbagi, Howard J. Hamilton
Recent research has focused on applying blockchain technology to solve security-related problems in Internet of Things (IoT) networks. However, implementing blockchain technology directly on IoT networks is prone to high overheads and energy-expensive operations. Therefore, in this paper, we use edge computing technology to avoid these problems. We also propose a novel Trust-based Access Control Mechanism for Edge-IoT Networks using Blockchain technology (named TABI) to implement end-to-end security in resource-constrained IoT networks. The TABI mechanism utilizes both access control and trust evaluation mechanisms to mitigate the impact of malicious IoT users and devices. Additionally, it incorporates permissioned Hyperledger blockchain technology to provide an added layer of security through authentication. The trust evaluation mechanism is implemented as a trust calculation contract (TCC) on the edge devices using Hyperledger Composer. The access control mechanism employs an Attribute-based Access Control (ABAC) mechanism, which is implemented on the Hyperledger blockchain using two smart contracts: the attribute contract (AC) and the access control contract (ACC). We implement a proof-of-concept (PoC) implementation using Hyperledger Caliper (a benchmark testing tool) and Docker images. Our evaluation includes five analyses: Trust Evaluation Mechanism, Access Control Mechanism, Security, Blockchain, and IoT Applications. Through this evaluation, we highlight the effectiveness of TABI in terms of throughput, latency, detection of malicious IoT devices, and resource consumption of the IoT devices. Our analyses demonstrate that TABI is particularly useful in IoT applications that require low latency and resource efficiency.
This thesis addresses the issue of semantic representation of the deployment environment of a smart contract and the integration of semantic licensing from the Data Licenses Clearance Center (DALICC) library. This research is divided into four sections for the following reasons: First, we concentrated on how smart contracts develop on the blockchain and some additional information about this system. Second, we show how blockchain and semantic web technology can work together. It focuses on several methods for indexing and running Ethereum blockchain smart contracts. The third segment, meanwhile, focuses on DALICC as a framework for identifying licensing conflicts and cutting down on the price of rights clearance. In the final piece, we created a DApp to describe a semantic model of these installations and connect semantic licensing with content using smart contracts.
Different from “read” based Web1 and “read-write” based Web2, “read-write-own” based Web3 is proposed as a typical user-centric internet to open the new generation of World Wide Web, which is expected to not allow the power to rest with a few big internet companies. Generally, Web3 is decentralized and semantic depending on user behavior, and thus the zero-trust architecture should be created initially. To hasten its arrival, a comprehensive discussion on its architecture and enabling technologies is inspired. Specifically, to access Web3, it is essential to study how to establish an identity management system. Meanwhile, for resource description and data verification, it is necessary to set up decentralized identifiers (DID), and link the data to identifiers in the form of DID document. In particular, a decentralized network operating system is an indispensable underlying technology for Web3, incorporating concepts such as decentralization and user-driven philosophy. Therefore, the corresponding technologies for the operating system such as blockchain and distributed ledger technology should be further studied and developed. Moreover, in order to reduce the consensus cost, a large-scale incentive mechanism is also the basis of long-term sustainability, which can attract and motivate distributed players to participate in the maintenance of Web3. Last but not the least, Web3 is built on a physical infrastructure relying on communication, networking, storage and computing, which is crucial to establishing an effective and secure Web3. This encourages us to study communication, networking, storage and computing in Web3, as well as the specific requirements of running Web3.
Tariq Alsboui, Muhammad Hussain, Hussain Al-Aqrabi, Richard Hill · 5 authors
With the vast development of Internet-of-Things (IoT) ecosystem, various types of information, such as healthcare records and physical resources, are integrated for different types of applications. Due to the sheer number of connected IoT devices, which generate a large amount of data, Distributed Ledger Technology, such as Blockchain and IOTA have been recently applied in developing access control models, yet they involve significant energy due to mining, low throughput, non-scalable, and computational overhead that is not acceptable for IoT resource-constrained devices. In this paper, we propose a Scalable Decentralized and Lightweight Access Control framework (SDAC) by using the IOTA platform. IOTA is an emerging distributed ledger technology that has significant features for IoT, such as zero fees transactions, scalability, security and energy efficiency. The proposed SDAC aims to improve security, authorize, and authenticate users when accessing data by using the IOTA Masked Authenticated Messaging (MAM) protocol. MAM ensures access control by encrypting and granting permission to only authorized users. The experimental results indicate that IOTA MAM is a feasible solution that can be used for managing authorization in the IoT domain.
Decentralized Applications (DApps) have seen exponential growth in the past decade leading to a new paradigm known as Web3. Web3 is the ecosystem formed by the execution of multiple DApps. Blockchains offer a platform for DApp executions. However, the performance and security of current blockchains is limited and impair the adoption of Web3. More specifically, for demanding DApp workloads, modern blockchains perform poorly or lose transactions. This thesis presents various contributions to enhance blockchain performance and security to widen the adoption of Web3. To enhance blockchain performance for DApp executions, we first present the Smart Redbelly Blockchain (SRBB). SRBB enhances DApp performance by reducing blockchain congestion. SRBB alone is not sufficient to service multiple demanding DApp workloads. Therefore, we introduce a DApp-oriented dynamic transparent sharding mechanism that concurrently execute DApps in separate shards. To boost the DApp performance of SRBB, we present a decoupled variant of SRBB known as Collachain. While blockchain performance is critical, existing blockchain designs are vulnerable to the formation of an oligarchy in the governance that can dictate the outcome of the protocol. Such an oligarchy can lead to the insecure execution of DApps, impairing the adoption of Web3. To mitigate the formation of an oligarchy in blockchain governance, we finally present a proportional governance protocol that proportionally elects a diverse set of governors to mitigate an oligarchy in the governance process.
Feifei Guo, Guohua Shen, Zhiqiu Huang, Yang Yang · 6 authors
With the advent of IoT technology, the dynamic nature of IoT devices has introduced new obstacles to access control. It is essential to consider the security requirements of the actual physical environment, rendering the traditional access control approach centered on the information space. In the IoT ecosystem, there are several issues such as the dynamics of devices frequently entering and leaving, the lack of computing and storage capacity, and distributed deployment. To address these challenges, this paper proposes the Domain Attribute Based Access Control(DABAC) that incorporates domain elements to implement the physical location limitation of dynamic devices. Moreover, an intelligent gateway is utilized to divide the physical area and act as a proxy to achieve regional device management, automatic networking of devices in the domain, and the dynamic expansion of the sensor network resulting from device entry or exit. Then, given the distributed deployment of devices, smart contracts are employed to deploy access control mechanisms and construct a trusted environment to mitigate threats such as single points of failure. Finally, the DABAC is implemented on the Ethereum platform, simulating a smart medical situation. The experimental results demonstrate that the proposed solution effectively addresses the problem of access control of device dynamics in an untrusted IoT environment while maintaining system security.
Abstract—This paper investigates the integration of Zero-Knowledge Proofs (ZKP) and OAuth 2.0 to enhance anonymity and security in multi-agent distributed systems. We propose an approach that allows agents to authenticate and prove possession of specific data without revealing the underlying details. Additionally, we outline a potential access control strategy using ZKP for anonymity, allowing agents to validate their access rights without identity exposure. When combined with OAuth 2.0, this mechanism provides a framework for secure data access. While the proposed methods offer promising solutions to security, privacy, and anonymity challenges in multi-agent systems, they also highlight the need for further research and validation to confirm their effectiveness.
Carmit Hazay, Muthuramakrishnan Venkitasubramaniam, Mor Weiss
Abstract Distributed zero-knowledge (dZK) proofs, recently introduced by Boneh et al. (CRYPTO‘19), allow a prover $$\mathcal{P}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>P</mml:mi> </mml:math> to prove NP statements on an input x , which is distributed between k verifiers $$\mathcal{V}_1,\ldots ,\mathcal{V}_k$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mn>1</mml:mn> </mml:msub> <mml:mo>,</mml:mo> <mml:mo>…</mml:mo> <mml:mo>,</mml:mo> <mml:msub> <mml:mi>V</mml:mi> <mml:mi>k</mml:mi> </mml:msub> </mml:mrow> </mml:math> , where each $$\mathcal{V}_i$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>V</mml:mi> <mml:mi>i</mml:mi> </mml:msub> </mml:math> holds only a piece of x . As in standard ZK proofs, dZK proofs guarantee Completeness when all parties are honest; Soundness against a malicious prover colluding with t verifiers; and Zero Knowledge against a subset of t malicious verifiers, in the sense that they learn nothing about the NP witness and the input pieces of the honest verifiers. Unfortunately, dZK proofs provide no correctness guarantee for an honest prover against a subset of maliciously corrupted verifiers. In particular, such verifiers might be able to “frame” the prover, causing honest verifiers to reject a true claim. This is a significant limitation, since such scenarios arise naturally in dZK applications, e.g., for proving honest behavior, and such attacks are indeed possible in existing dZKs (Boneh et al., CRYPTO‘19). We put forth and study the notion of strong completeness for dZKs, guaranteeing that true claims are accepted even when t verifiers are maliciously corrupted. We then design strongly-complete dZK proofs in the honest-majority setting using the “MPC-in-the-head” paradigm of Ishai et al. (STOC‘07), providing a novel analysis that exploits the unique properties of the distributed setting. To demonstrate the usefulness of strong completeness, we present several applications in which it is instrumental in obtaining security. First, we construct a certifiable version of Verifiable Secret Sharing (VSS), which is a VSS in which the dealer additionally proves that the shared secret satisfies a given NP relation. Our construction withstands a constant fraction of corruptions, whereas a previous construction of Ishai et al. (TCC‘14) required $$k={\textsf{poly}}\left( t\right) $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>k</mml:mi> <mml:mo>=</mml:mo> <mml:mi>poly</mml:mi> <mml:mfenced> <mml:mi>t</mml:mi> </mml:mfenced> </mml:mrow> </mml:math> . We also design a reusable version of certifiable VSS that we introduce, in which the dealer can prove an unlimited number of predicates on the same shared secret. Finally, we extend a compiler of Boneh et al. (CRYPTO‘19), who used dZKs to transform a class of “natural” semi-honest protocols in the honest-majority setting into maliciously secure ones with abort. Our compiler uses strongly-complete dZKs to obtain identifiable abort.
Franck Cassez, Joanne Fuller, Milad K. Ghale, David J. Pearce · 5 authors
The Ethereum protocol implements a replicated state machine. The network participants keep track of the system state by: 1) agreeing on the sequence of transactions to be processed and 2) computing the state transitions that correspond to the sequence of transactions. Ethereum transactions are programs, called smart contracts, and computing a state transition requires executing some code. The Ethereum Virtual Machine (EVM) provides this capability and can execute programs written in EVM bytecode. We present a formal and executable semantics of the EVM written in the verification-friendly language Dafny: it provides (i) a readable, formal and verified specification of the semantics of the EVM; (ii) a framework to formally reason about bytecode.
In recent years, Attribute-Based Access Control (ABAC) has become popular in organizations implementing fine grained control of access to their data, systems and other resources. However, migration from existing non-ABAC systems is not only time consuming, it also requires significant redesigning of application code. Providing ABAC as a cloud service can help in this process by eliminating the need for ab initio development of ABAC support in already running stable applications. While attractive from a management perspective, there is always a concern for security of the cloud service itself. In this paper, we propose ABAC as a service with security guarantee provided through the use of blockchain, specifically Ethereum. We build an effective functionality that enables user organizations to verify whether its access control data as well as access mediation decisions made by the cloud service were indeed done in an authorized manner. All the changes to the various ABAC components along with access history are added to the Ethereum blockchain using efficiently written smart contracts in Solidity. We have developed a prototype system on the Rinkeby Ethereum test network. Experimental results demonstrate that the proposed approach is effective and incurs only a modest additional cost.
Stefan More, Sebastian Ramacher, Lukas Alber, Marco Herzl
Authentication, authorization, and trust verification are central parts of an access control system. The conditions for granting access in such a system are collected in access policies. Since access conditions are often complex, dedicated languages -- policy languages -- for defining policies are in use. However, current policy languages are unable to express such conditions having privacy of users in mind. With privacy-preserving technologies, users are enabled to prove information to the access system without revealing it. In this work, we present a generic design for supporting privacy-preserving technologies in policy languages. Our design prevents unnecessary disclosure of sensitive information while still allowing the formulation of expressive rules for access control. For that we make use of zero-knowledge proofs (NIZKs). We demonstrate our design by applying it to the TPL policy language, while using SNARKs. Also, we evaluate the resulting ZK-TPL language and its associated toolchain. Our evaluation shows that for regular-sized credentials communication and verification overhead is negligible.
Scientific and commercial endeavors could benefit from cross-organizational, decentralized collaboration, which becomes the key to innovation. This work addresses one of its challenges, namely efficient access control to assets for distributed data processing among autonomous data centers. We propose a group membership management framework dedicated for realizing access control in decentralized environments. Its novelty lies in a synergy of two concepts: a decentralized knowledge base and an incremental indexing scheme, both assuming a P2P architecture, where each peer retains autonomy and has full control over the choice of peers it cooperates with. The extent of exchanged information is reduced to the minimum required for user collaboration and assumes limited trust between peers. The indexing scheme is optimized for read-intensive scenarios by offering fast queries -- look-ups in precomputed indices. The index precomputation increases the complexity of update operations, but their performance is arguably sufficient for large organizations, as shown by conducted tests. We believe that our framework is a major contribution towards decentralized, cross-organizational collaboration.
Andrea Giacobino, David Grierson, Gianguido Sorà, Har Preet Singh · 7 authors
The key to the emerging digital society and economy is digital identity, a fundamental component of digital transformation in representing any real-world entity in digital form. An effective digital identity is essential to secure a successful digital future, especially as the demand for digital services grows.Since the genesis of digital identification, numerous identity management (IdM) systems have been developed and enforced to address the increasing need to manage identities based on the needs of individuals and organizations. This advancement of IdM systems offers an incremental process that leads the user to gain control of identity ownership and personal data while raising identity management concerns such as sovereignty, storage, access control, security, privacy, and safeguarding. Self-sovereign identity (SSI), recently recognized as a promising IdM, can provide sovereignty to the identity owner while addressing these concerns.The Elesto protocol is an emerging open-source, public permissionless blockchain-based implementation that uses SSI for identity management for users, organizations, and other entities. The protocol leverages W3C specifications for decentralized identifiers (DID), verifiable credentials (VC), DIDComm messaging specifications, and SSI agents.The Elesto protocol is an application-specific blockchain implementation using the Cosmos SDK framework, Tendermint Proof-of-Stake (PoS) consensus, the Inter-Blockchain Communication protocol (IBC), and design satisfies all of the fundamental requirements and principles of SSI.This paper presents the design and implementation of the Elesto protocol as an identity infrastructure. Three use cases illustrate how the protocol helps overcome the highlighted problems by decentralizing or extending functionalities in the blockchain infrastructure.
A medical record is an important part of a patient’s follow-up. It comprises healthcare professionals’ views, prescriptions, analyses, and all information about the patient. Several players, including the patient, the doctor, and the pharmacist, are involved in the process of sharing, and managing this file. Any authorized individual can access the electronic medical record (EMR) from anywhere, and the data are shared among various health service providers. Sharing the EMR requires various conditions, such as security and confidentiality. However, existing medical systems may be exposed to system failure and malicious intrusions, making it difficult to deliver dependable services. Additionally, the features of these systems represent a challenge for centralized access control methods. This paper presents SEMRAchain a system based on Access control (Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC)) and a smart contract approach. This fusion enables decentralized, fine-grained, and dynamic access control management for EMR management. Together, blockchain technology as a secure distributed ledger and access control provides such a solution, providing system stakeholders with not just visibility but also trustworthiness, credibility, and immutability.
Tobias Adrian, Federico Grinberg, Tommaso Mancini Griffoli, Robert M. Townsend · 5 authors
Cross-border payments can be slow, expensive, and risky. They are intermediated by counterparties in different jurisdictions which rely on costly trusted relationships to offset the lack of a common settlement asset as well as common rules and governance. In this paper, we present a vision for a multilateral platform that could improve cross-border payments, as well as related foreign exchange transactions, risk sharing, and more generally, financial contracting. The approach is to leverage technological innovations for public policy objectives. A common ledger, smart contracts, and encryption offer significant gains to market efficiency, completeness, and access, as well as to transparency, transaction and compliance costs, and safety. This paper is a first step aiming to stimulate further work in this space.
Advances in monitoring, sensing, control, and communication allow the use of Smart Grid. It enables smart metering applications, substation event and alarm updates, vehicle-tovehicle (V2V), and vehicle-to-network (V2G) energy transactions, among others. However, the data used is sensitive and communication between entities must be reliable and secure. For this, the Internet uses the Public Key Infrastructure (ICP) in which the communicating parties must have a digital certificate issued by a certification authority (CA). However, it has a centralized architecture with a single point of failure. An alternative to this is the use of distributed technologies and one that stands out is Blockchain. It is a technology that allows trusted communication between untrusted entities without a centralized third party. Also, Blockchain is a chronological sequence of blocks linked through the hash of each one. This characteristic ensures data integrity and immutability. Therefore, Blockchain is a powerful technology for recording data like access control rules. This work utilizes Blockchain to provide a framework applying the Smart Contract concept for a Role-Based Access Control (RBAC) system. Also, it uses the framework Truffle to test the Smart Contract functionalities and presents a study case of the proposal (KIM et al., 2019) together with this work. In counterpart to the related works, this work does not have a single-point of failure.
Javier Godoy, Juan Pablo Galeotti, Diego Garbervetsky, Sebastián Uchitel
Smart contracts are immutable programs deployed on the blockchain that can manage significant assets. Because of this, verification and validation of smart contracts is of vital importance. Indeed, it is industrial practice to hire independent specialized companies to audit smart contracts before deployment. Auditors typically rely on a combination of tools and experience but still fail to identify problems in smart contracts before deployment, causing significant losses. In this paper, we propose using predicate abstraction to construct models which can be used by auditors to explore and validate smart contact behaviour at the function call level by proposing predicates that expose different aspects of the contract. We propose predicates based on requires clauses and enum-type state variables as a starting point for contract validation and report on an evaluation on two different benchmarks.
Daniël Reijsbergen, Aung Htein Maw, Zheng Yang, Tien Tuan Anh Dinh · 5 authors
Users today expect more security from services that handle their data. In addition to traditional data privacy and integrity requirements, they expect transparency, i.e., that the service's processing of the data is verifiable by users and trusted auditors. Our goal is to build a multi-user system that provides data privacy, integrity, and transparency for a large number of operations, while achieving practical performance. To this end, we first identify the limitations of existing approaches that use authenticated data structures. We find that they fall into two categories: 1) those that hide each user's data from other users, but have a limited range of verifiable operations (e.g., CONIKS, Merkle2, and Proofs of Liabilities), and 2) those that support a wide range of verifiable operations, but make all data publicly visible (e.g., IntegriDB and FalconDB). We then present TAP to address the above limitations. The key component of TAP is a novel tree data structure that supports efficient result verification, and relies on independent audits that use zero-knowledge range proofs to show that the tree is constructed correctly without revealing user data. TAP supports a broad range of verifiable operations, including quantiles and sample standard deviations. We conduct a comprehensive evaluation of TAP, and compare it against two state-of-the-art baselines, namely IntegriDB and Merkle2, showing that the system is practical at scale.
Zhe Tu, Huachun Zhou, Kun Li, Haoxiang Song · 5 authors
The rapid development of the Internet of Things (IoT) has dramatically increased the number of distributed IoT devices and users. Trust and Reputation Model (TRM) is a well-known technique for improving the security of IoT, which detects malicious attacks by evaluating user behavior. Since traditional distributed TRMs lack secure and reliable data sharing mechanisms, some works have integrated the TRMs into the trusted blockchains. Nevertheless, they have not realized the security requirements of the comprehensive assessment of user behavior and dynamic evaluation of reputation. Therefore, this paper introduces a Blockchain-based Trust and Reputation Model (BTRM), which evaluates user reputation from many aspects and can resist multiple malicious attacks in the distributed network. Second, we propose a novel Dynamic Evaluation Mechanism (DEM), which reduces the number of reputation evaluations without degrading network security and builds a trusting foundation between long-term inactive users and the network. Eventually, we deploy the proposed model DEM-BTRM in a prototype system of Hyperledger Fabric and compare it with existing reputation evaluation methods. The results show that the DEM-BTRM can comprehensively evaluate user behavior and dynamically detect malicious attacks.
Javier José Díaz Rivera, Talha Ahmed Khan, Waleed Akbar, Muhammad Afaq · 5 authors
Zero Trust Networking (ZTN) is a security model where no entity in a network infrastructure is trusted. The first bastion of security for achieving ZTN is to have strong identity verification. Several standard methods for assuring a robust identity exist (E.g., OAuth2.0, OpenID Connect). These standards employ the use of JSON Web Tokens (JWT) during the authentication process. However, the use of JWT for One Time Token (OTT) enrollment has a latent security issue. A JWT can be intercepted by a third party and the information of the payload can be exposed, revealing the details of the enrollment server. Furthermore, an intercepted JWT could be used for enrollment by an impersonator as long as the JWT remains active. Our proposed mechanism aims to secure the ownership of the OTT by including the JWT as encrypted metadata into a Non-Fungible Token (NFT). The mechanism uses the blockchain Public Key of the intended owner for encrypting the JWT, and the blockchain assures the JWT ownership by mapping it to the intended owner's blockchain public address. Our proposed mechanism is applied to an emerging Zero Trust framework (OpenZiti) alongside a permissioned Ethereum blockchain using Hyperledger Besu. The Zero Trust Framework provides the enrollment functionality, while our proposed mechanism based on blockchain and NFT assures the secure distribution of OTTs that is used for the enrollment of identities.