Study and Design of Blockchain Based Decentralized Trust Management System for Secure Transactions
Varun M. Deshpande · HAL (Le Centre pour la Communication Scientifique Directe) · 2020
In the context of modern connected world, the concept of atomic data transfer/transaction has been completely redefined. Traditional distributed databases solve the issue of data safety through classical Atomicity, Consistency, Isolation and Durability (ACID) properties. However, the complex issue of transaction security remains difficult to address. Introducing blockchain (BC) as distributed database partially solves the problem but another issue arises i.e., BC’s modeling and evaluation. For e.g., what parameter values are ideal, is the selected blockchain framework compatible, etc.In this thesis, we solve it through dimensioning of BC using graph theory. With binomial distribution and preferential attachment models, we model the underlying BC P2P network to reduce topology control overhead while ensuring high flexibility, fast reconfigurability, connectivity, small diameter and clustering. Next, to reduce the no. of connections per peer, we establish ideal bounds on outbound and inbound connections that still guarantee P2P network feasibility and connectivity using r-out digraphs. For an already developed BC framework, we evaluate its applicability through topology mapping. We demonstrate the efficiency of our approach using our BTCmap framework applied to Bitcoin and present its real captured snapshot.However, using BC alone cannot holistically secure transaction as it only guarantees data immutability whereas in most scenarios, the data has also to be secured at point of generation and usage. Further, BC has high overhead and cannot penetrate to lower levels in a system. To mitigate this, we propose the use of Secure Element (SE) to establish “root of trust”, following the “secure by design” paradigm.Using these two technologies as the base of our proposed decentralized system, we apply it to three disparate fields. In Smart Grids, we address the problem of designing of distributed marketplace using the concepts of blockchain, SE, applied smart contracts, escrow accounts. We also address the issue of large data storage on blockchain for DR and centralization in DR allotment by designing a decentralized autonomous bidding system. We also propose a fair and efficient DR allotment algorithm whose execution time is less than 1 minute for more than 20k participants.Next, we apply our BC-SE based Safeguarding Framework (SaFe) to smart vehicles and address the problem of insecure Execution and Storage Environment within the smart vehicle. With SaFe, we show, how non-repudiable responsibility can be enforced. This ensures that when regulators audit the data, its veracity is undeniable. The issue of secure firmware update and key management is also solved while improving performance.In IoT, we apply our SE BC Stratagem (SEBS) to solve the pressing issue of holistic data security in resource constrained devices i.e., securing data at all 3 points viz., generation, storage, and usage while maintaining very low overhead and improving performance. We also address the niche issue of verification of blockchain data where a remote device which receives data from blockchain through an intermediary, does not have resources and online connectivity to verify it. By proposing SEOVA's double signature algorithm using the technology of SE, we successfully solve this issue without compromising on security and privacy.In the last leg, we solve the classical problem of sensor monitoring where data is transmitted using "limited transmit" method which results in aperiodicity in transmit patterns for various onsite sensors. The system on the other end must distinguish between two scenarios i.e. 1) data is not transmitted because transmission conditions are unmet, and 2) data is not transmitted because of an error on remote site. Given the same outcome for both cases, our SE-based PulSec framework, cleverly solves this problem while maintaining extremely low overhead (bandwidth=7.73 B/s, memory=464 B, time=500 ms) and zero false-positive cases