Key exchange with the help of a public ledger

Blockchains and other public ledger structures promise a new way to create globally consistent event logs and other records. We make use of this consistency property to detect and prevent man-in-the-middle attacks in a key exchange such as Diffie-Hellman or ECDH. Essentially, the MitM attack creates an inconsistency in the world views of the two honest parties, and they can detect it with the help of the ledger. Thus, there is no need for prior knowledge or trusted third parties apart from the distributed ledger. To prevent impersonation attacks, we require user interaction. It appears that, in some applications, the required user interaction is reduced in comparison to other user-assisted key-exchange protocols

Blocks\u27 Network: Redesign Architecture based on Blockchain Technology

The Internet is a global network that uses communication protocols. It is considered the most important system reached by humanity, which no one can abandon. However, this technology has become a weapon that threatens the privacy of users, especially in the client-server model, where data is stored and managed privately. Additionally, users have no power over their data that store in a private server, which means users’ data may interrupt by government or might be sold via service provider for-profit purposes. Furthermore, blockchain is a technology that we can rely on to solve issues related to client-server model if appropriately used. However, blockchain technology uses consensus protocol, which is used for creating an incontrovertible system of agreement between members across a distributed network. Thus, the consensus protocol is used to slow all member down from generating too fast in order to control the network creation pattern, which leads to scalability and latency problems. The proposed system will present a platform that leverages modernize blockchain called Blocks’ Network. The system is taking into consideration the issues related to privacy and confidentiality from the client-side model, and scalability and latency issues from the blockchain technology side. Blocks’ network is a public and a permissioned network that use a multi-dimensional hash to generate multiple chains for the purpose of a systematic approach. The proposed platform is an assembly point for users to create a decentralized network using P2P protocols. The system has high data flow due to frequent use by participants (for example, the use of the Internet). Besides, the system will store all traffic of the network overtly via Blocks’ Network

A Flexible Network Approach to Privacy of Blockchain Transactions

For preserving privacy, blockchains can be equipped with dedicated mechanisms to anonymize participants. However, these mechanism often take only the abstraction layer of blockchains into account whereas observations of the underlying network traffic can reveal the originator of a transaction request. Previous solutions either provide topological privacy that can be broken by attackers controlling a large number of nodes, or offer strong and cryptographic privacy but are inefficient up to practical unusability. Further, there is no flexible way to trade privacy against efficiency to adjust to practical needs. We propose a novel approach that combines existing mechanisms to have quantifiable and adjustable cryptographic privacy which is further improved by augmented statistical measures that prevent frequent attacks with lower resources. This approach achieves flexibility for privacy and efficency requirements of different blockchain use cases.Comment: 6 pages, 2018 IEEE 38th International Conference on Distributed Computing Systems (ICDCS

Data Hiding and Its Applications

Data hiding techniques have been widely used to provide copyright protection, data integrity, covert communication, non-repudiation, and authentication, among other applications. In the context of the increased dissemination and distribution of multimedia content over the internet, data hiding methods, such as digital watermarking and steganography, are becoming increasingly relevant in providing multimedia security. The goal of this book is to focus on the improvement of data hiding algorithms and their different applications (both traditional and emerging), bringing together researchers and practitioners from different research fields, including data hiding, signal processing, cryptography, and information theory, among others

Blockchain in maritime cybersecurity

Blockchain technologies can be used for many different purposes from handling large amounts of data to creating better solutions for privacy protection, user authentication and a tamper proof ledger which lead to growing interest among industries. Smart contracts, fog nodes and different consensus methods create a scalable environment to secure multi-party connections with equal trust of participanting nodes’ identity. Different blockchains have multiple options for methodologies to use in different environments. This thesis has focused on Ethereum based open-source solutions that fit the remote pilotage environment the best. Autonomous vehicular networks and remote operatable devices have been a popular research topic in the last few years. Remote pilotage in maritime environment is persumed to reach its full potential with fully autonomous vessels in ten years which makes the topic interesting for all researchers. However cybersecurity in these environments is especially important because incidents can lead to financial loss, reputational damage, loss of customer and industry trust and environmental damage. These complex environments also have multiple attack vectors because of the systems wireless nature. Denial-of-service (DoS), man-in-the-middle (MITM), message or executable code injection, authentication tampering and GPS spoofing are one of the most usual attacks against large IoT systems. This is why blockchain can be used for creating a tamper proof environment with no single point-of-failure. After extensive research about best performing blockchain technologies Ethereum seemed the most preferable for decentralised maritime environment. In comparison to most of 2021 blockchain technologies that have focused on financial industries and cryptocurrencies, Ethereum has focused on decentralizing applications within many different industries. This thesis provides three Ethereum based blockchain protocol solutions and one operating system for these protocols. All have different features that add to the base blockchain technology but after extensive comparison two of these protocols perform better in means of concurrency and privacy. Hyperledger Fabric and Quorum provide many ways of tackling privacy, concurrency and parallel execution issues with consistent high throughput levels. However Hyperledger Fabric has far better throughput and concurrency management. This makes the solution of Firefly operating system with Hyperledger Fabric blockchain protocol the most preferable solution in complex remote pilotage fairway environment

Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments

Decentralized systems are a subset of distributed systems where multiple authorities control different components and no authority is fully trusted by all. This implies that any component in a decentralized system is potentially adversarial. We revise fifteen years of research on decentralization and privacy, and provide an overview of key systems, as well as key insights for designers of future systems. We show that decentralized designs can enhance privacy, integrity, and availability but also require careful trade-offs in terms of system complexity, properties provided, and degree of decentralization. These trade-offs need to be understood and navigated by designers. We argue that a combination of insights from cryptography, distributed systems, and mechanism design, aligned with the development of adequate incentives, are necessary to build scalable and successful privacy-preserving decentralized systems

Blockchain-based end-to-end encryption for Matrix instant messaging

Privacy and security in online communication is an important topic today, especially in the context of instant messaging. A lot of progress has been made in recent years to ensure that conversations are secure against attacks by third parties, but privacy from the service provider itself remains difficult. There are a number of solutions offering end-to-end encryption, but most of them rely on a centralized server, proprietary clients, or both. In order to have fully secure instant messaging conversations, a decentralized and end-to-end encrypted communication protocol is needed. This means there is no single point of control, and each message is encryped directly on the user's device such that only the recipient can decrypt it. This work proposes an end-to-end encryption system for the Matrix protocol based on blockchain technology. Matrix is a decentralized protocol and network for real-time communication that is currently mostly used for instant messaging. This protocol was selected because of its versatility and extensibility. Using the Secret Store feature in OpenEthereum, the proposed system encrypts data using keys stored on the Ethereum blockchain. Access control to the keys is also handled by the Secret Store via a smart contract. The proposed encryption system has multiple advantages over alternative schemes: The underlying blockchain technology reduces the risk of data loss because of its decentralized and distributed nature. Thanks to the use of smart contracts this system also allows for the creation of an advanced access control system to decryption keys. In order to test and analyze the proposed design, a reference implementation was created in the form of a library. This library can be used for future research, but also as a building block for different applications to easily implement end-to-end encryption based on blockchain technology

Securing the Edges of IoT Networks: a Scalable SIP DDoS Defense Framework with VNF, SDN, and Blockchain

An unintended consequence of the global deployment of IoT devices is that they provide a fertile breeding ground for IoT botnets. An adversary can take advantage of an IoT botnet to launch DDoS attacks against telecommunication services. Due to the magnitude of such an attack, legacy security systems are not able to provide adequate protection. The impact ranges from loss of revenue for businesses to endangering public safety. This risk has prompted academia, government, and industry to reevaluate the existing de- fence model. The current model relies on point solutions and the assumption that adversaries and their attacks are readily identifiable. But adversaries have challenged this assumption, building a botnet from thousands of hijacked IoT devices to launch DDoS attacks. With bot- net DDoS attacks there are no clear boundary where the attacks originate and what defensive measures to use. The research question is: in what ways programmable networks could defend against Session Initiation Protocol (SIP) Distributed Denial-of-Service (DDoS) flooding attacks from IoT botnets? My significant and original contribution to the knowledge is a scalable and collaborative defence framework that secures the edges of IoT networks with Virtual Network Function (VNF), Software-Defined Networking (SDN), and Blockchain technology to prevent, detect, and mitigate SIP DDoS flooding attacks from IoT botnets. Successful experiments were performed using VNF, SDN, and Blockchain. Three kinds of SIP attacks (scan, brute force, and DDoS) were launched against a VNF running on a virtual switch and each was successfully detected and mitigated. The SDN controller gathers threat intelligence from the switch where the attacks originate and installs them as packet filtering rules on all switches in the organisation. With the switches synchronised, the same botnet outbreak is prevented from attacking other parts of the organisation. A distributed application scales this framework further by writing the threat intelligence to a smart contract on the Ethereum Blockchain so that it is available for external organisations. The receiving organisation retrieves the threat intelligence from the smart contract and installs them as packet filtering rules on their switches. In this collaborative framework, attack detection/mitigation efforts by one organisation can be leveraged as attack prevention efforts by other organisations in the community

Blockchains For Publicizing Available Scientific Datasets

This thesis explores the effectiveness of blockchain technology for advertisement of scientific data. Recently the advancement in hardware and software for data processing increases the supply and demand for huge data sets. Such data may be widely distributed, and not immediately available to the scientists who need it. We need a method of advertising available datasets to interested parties. Blockchains are a recent innovation developed by the cryptocurrency community, but are increasingly applied to other problem domains. Due to their currency heritage, however, the properties of blockchains do not always lend themselves to new applications. We have developed a prototype dapp (distributed application) to advertise available scientific datasets using metadata. A private ethereum blockchain is used to distribute metadata to users, while an ethereum contract matches dataset providers with consumers. Lastly, a conceptual currency is used to incentivize efficient resource selection

Hummingbird: A Flexible and Lightweight Inter-Domain Bandwidth-Reservation System

The current Internet lacks a bandwidth-reservation infrastructure that enables fine-grained inter-domain reservations for end hosts. This is hindering the provisioning of quality-of-service guarantees for real-time applications like video calls and gaming, cloud-based systems, financial transactions, telesurgery, and other remote applications that benefit from reliable communication. This paper introduces Hummingbird, a novel lightweight inter-domain bandwidth-reservation system that addresses several shortcomings of previous designs. Hummingbird supports flexible and composable reservations and enables end-to-end guarantees without requiring autonomous systems to manage reservations for their endhosts. Previous systems tied reservations to autonomous-system numbers or network addresses, which limits the flexibility of reservations. In contrast, our system decouples reservations from network identities and, as a result, the control plane from the data plane. This design choice facilitates multiple co-existing control-plane mechanisms and enables innovative approaches, such as a control plane based on blockchain smart contracts that offers tradeable bandwidth-reservation assets and end-to-end guarantees. The data-plane design ensures simplicity for efficient processing on border routers, which streamlines implementation, deployment, and traffic policing while maintaining robust security properties.Comment: 14 pages, 7 figure