More Like this

1. Blockumulus: A Scalable Framework for Smart Contracts on the Cloud

   https://doi.org/10.1109/ICDCS51616.2021.00064  

   Ivanov, Nikolay; Yan, Qiben; Wang, Qingyang (July 2021, 2021 IEEE 41st International Conference on Distributed Computing Systems (ICDCS))

   Public blockchains have spurred the growing popularity of decentralized transactions and smart contracts, especially on the financial market. However, public blockchains exhibit their limitations on the transaction throughput, storage availability, and compute capacity. To avoid transaction gridlock, public blockchains impose large fees and per-block resource limits, making it difficult to accommodate the ever-growing high transaction demand. Previous research endeavors to improve the scalability and performance of blockchain through various technologies, such as side-chaining, sharding, secured off-chain computation, communication network optimizations, and efficient consensus protocols. However, these approaches have not attained a widespread adoption due to their inability in delivering a cloud-like performance, in terms of the scalability in transaction throughput, storage, and compute capacity. In this work, we determine that the major obstacle to public blockchain scalability is their underlying unstructured P2P networks. We further show that a centralized network can support the deployment of decentralized smart contracts. We propose a novel approach for achieving scalable decentralization: instead of trying to make blockchain scalable, we deliver decentralization to already scalable cloud by using an Ethereum smart contract. We introduce Blockumulus, a framework that can deploy decentralized cloud smart contract environments using a novel technique called overlay consensus. Through experiments, we demonstrate that Blockumulus is scalable in all three dimensions: computation, data storage, and transaction throughput. Besides eliminating the current code execution and storage restrictions, Blockumulus delivers a transaction latency between 2 and 5 seconds under normal load. Moreover, the stress test of our prototype reveals the ability to execute 20,000 simultaneous transactions under 26 seconds, which is on par with the average throughput of worldwide credit card transactions. 

   more » « less
2. A Game Theoretical Analysis of Non-Linear Blockchain System

   https://doi.org/10.5555/3463952.3463995  

   Chen, L.; Xu, L.; Gao, Z.; Sunny, A.; Kasichainula, K.; Shi, W. (May 2021, International Conference on Autonomous Agents and MultiAgent Systems)

   null (Ed.)

   Recent advances in the blockchain research have been made in two important directions. One is refined resilience analysis utilizing game theory to study the consequences of selfish behavior of users (miners), and the other is the extension from a linear (chain) structure to a non-linear (graphical) structure for performance improvements, such as IOTA and Graphcoin. The first question that comes to mind is what improvements that a blockchain system would see by leveraging these new advances. In this paper, we consider three major properties for a blockchain system: α-partial verification, scalability, and finality-duration. We establish a formal framework and prove that no blockchain system can achieve ?-partial verification for any fixed constant ?, high scalability, and low finality-duration simultaneously. We observe that classical blockchain systems like Bitcoin achieves full verification (α=1) and low finality-duration, Ethereum 2.0 Sharding achieves low finality-duration and high scalability. We are interested in whether it is possible to partially satisfy the three properties. 

   more » « less
3. Auroch: Auction based Multipath Routing for Payment Channel Networks

   Ababneh, Mohammed; Kolachala Kartick; Vishwanathan, Roopa (July 2024, ACM Asia Conference on Computer and Communications Security (ACM AsiaCCS))

   The Bitcoin blockchain scalability problem has inspired several offchain solutions for enabling cryptocurrency transactions, of which Layer-2 systems such as payment channel networks (PCNs) have emerged as a frontrunner. PCNs allow for path-based transactions between users without the need to access the blockchain. These path-based transactions are possible only if a suitable path exists from the sender of a payment to the receiver. In this paper, we propose Auroch, a distributed auction-based pathfinding and routing protocol that takes into account the routing fees charged by nodes along a path. Unlike other routing protocols proposed for PCNs, Auroch takes routing fees into consideration. Auroch maximizes the profit that can be achieved by an intermediate node at the same time minimizing the overall payment cost for the sender. 

   more » « less
4. A Scalable Blockchain Framework for Secure Data and Computational Resource Management in SDN

   https://doi.org/10.1109/GCWkshp64532.2024.11100329  

   Das, Debashis; Landrum, La Chiara; Chatterjee, Pushpita; Ghosh, Uttam (December 2024, IEEE)

   The rapid evolution of Software-Defined Networking (SDN) has transformed network management by decoupling the control and data planes. It provides centralized control, enhanced flexibility, and programmability of network management services. However, this centralized control introduces security vulnerabilities and challenges related to data integrity, unauthorized access, and resource management. In addition, it brings forth significant challenges in secure and scalable data storage and computational resource management. These challenges are further increased by the need for real-time processing and the ever-increasing volume of data. To address these challenges, this paper presents a scalable blockchain-based framework for security and computational resource management in SDN architectures. The proposed framework ensures decentralized and tamper-resistant data handling and utilizes smart contracts for automated resource allocation. Due to the need for advanced security and scalability in SDN networks, this work incorporates sharding to improve parallel processing capabilities. The performance of sharded versus non-sharded blockchain systems under various network conditions is evaluated. Our findings demonstrate that the sharded blockchain model enhances scalability and throughput with robust security and fault tolerance. The framework is also assessed for its performance, scalability, and security to enhance SDN resilience against data breaches, malicious activities, and inefficient resource distribution. 

   more » « less
5. Securing blockchain-based timed data release against adversarial attacks

   https://doi.org/10.3233/JCS-230001  

   Wang, Jingzhe; Palanisamy, Balaji (November 2023, Journal of Computer Security)

   Sural, Shamik; Lu, Haibing (Ed.)

   Timed data release refers to protecting sensitive data that can be accessed only after a pre-determined amount of time has passed. While blockchain-based solutions for timed data release provide a promising approach for decentralizing the process, designing an attack-resilient timed-release service that is resilient to malicious adversaries in a blockchain network is inherently challenging. A timed-release service on a blockchain network is inevitably exposed to the risk of post-facto attacks where adversaries may launch attacks after the data is released in the blockchain network. Existing incentive-based solutions for timed data release in Ethereum blockchains guarantee protection under the assumption of a fully rational adversarial environment in which every peer acts rationally. However, these schemes fail invariably when even a single participating peer node in the protocol starts acting maliciously and deviates from the rational behavior. In this paper, we propose a systematic solution for attack-resilient and practical blockchain-based timed data release in a mixed adversarial environment, where both malicious adversaries and rational adversaries exist. We first propose an effective uncertainty-aware reputation measure to capture the behaviors of the peer involved in timed data release activities in the network. In light of such a measure, we present the design of a basic protocol that consists of two critical ingredients, namely reputation-aware peer recruitment and verifiable enforcement protocols. The former, prior to the start of the enforcement protocols, performs peer recruitment based on the reputation measure to make the design probabilistically attack-resilient to the post-facto attacks. The latter is responsible for contractually guarding the recruited peers at runtime by transparently reporting observed adversarial behaviors. However, the basic recruitment design is only aware of the reputation of the peers and it does not consider the working time schedule of the participating peers and as a result, it results in lower attack-resilience. To enhance the attack resilience further without impacting the verifiable enforcement protocols, we propose a temporal graph-based reputation-aware peer recruitment algorithm that carefully determines the peer recruitment plan to make the service more attack-resilient. In our proposed approach, we formally capture the timed data release service as a temporal graph and we develop a novel maximal attack-resilient path-finding algorithm on the temporal graph for the participating peers. We implement a prototype of the proposed approach using Smart Contracts and deploy it on the Ethereum official test network, Rinkeby. For extensively evaluating the proposed techniques, we perform simulation experiments to validate the effectiveness of the reputation-aware timed data release protocols as well as our proposed temporal-graph-based improvements. The results demonstrate the effectiveness and strong attack resilience of the proposed mechanisms and our approach incurs only a modest gas cost. 

   more » « less