This page summarizes my recent research on blockchain.
HEALTH INFORMATION EXCHANGE WITH BLOCKCHAIN AMID COVID-19-LIKE PANDEMICS
The COVID-19 pandemic is stress-testing existing health information exchange systems. There exists an increasing demand for sharing patient information and efficiently responding to patient medial data requests. Current health information technologies lack \textit{data fluidity}, especially for remotely sharing medical data beyond their protected, local data storage. This paper presents a blockchain-based data-sharing framework that leverages the properties of immutability and decentralization to ensure a secure, user-centric approach for accessing and controlling access to sensitive medical data. The proposed framework builds its foundations on a peer-to-peer network fueled by the distributed InterPlanetary File System combined with on-chain tagging, and on the use of cryptographic generation techniques for enabling a secure way of sharing medical data. The flow of information is orchestrated by a smart-contract deployed on a blockchain-based protocol to ensure traceability and data integrity. The effectiveness of the framework is demonstrated with the implementation of the framework over a pilot study.
K. Christodoulou, P. Christodoulou, Z. Zinonos, E. Carayannis, and S. A. Chatzichristofis, “HEALTH INFORMATION EXCHANGE WITH BLOCKCHAIN AMID COVID-19-LIKE PANDEMICS”, «16th IEEE International Conference on Distributed Computing in Sensor Systems, DCOSS», 15-17 June 2020, Los Angeles, United States, Accepted for Publication
RANDOMBLOCKS: A TRANSPARENT, VERIFIABLE BLOCKCHAIN-BASED ALGORITHM FOR RANDOM NUMBERS
Games-of-chance requires high-levels of trust between participants that is often uncertain and difficult to enforce. The unique characteristics introduced by the blockchain technology can be leveraged to inform a verifiable but transparent pseudo-random generation process that at the same time eliminates the need for an external trustee service or oracle to guarantee the fair execution of the process. In this paper, we propose a process that builds on a one-dimensional \textit{Cellular Automaton (CA)} where the evolution of the CA aligns with the evolution of a blockchain. Given an initial seed defined as the point in time where the evolution of the CA is triggered, the set of transition rules, along with the finite number of evolution steps, any external oracle is able to verify and backtrack (but not predict) the outcome of the process. The effectiveness of the implemented system is challenged against the Dieharder 3.31.1 and NIST SP 800-22 statistical testing suites that confirmed the existence of a set of statistical properties required to produce pseudo-random number sequences.
K. Christodoulou, S. A. Chatzichristofis, G. Ch. Sirakoulis, and P. Christodoulou, “RANDOMBLOCKS: A TRANSPARENT, VERIFIABLE BLOCKCHAIN-BASED ALGORITHM FOR RANDOM NUMBERS”, «Journal of Cellular Automata», 14(3-4), November 2019, pp 171-190.
PARKCHAIN: AN IOT PARKING SERVICE BASED ON BLOCKCHAIN
The IoT ecosystem is evolving quickly, developing several applications in different sectors. The majority of these applications use centralized infrastructures something that poses several challenges especially related to trust and data security. Recently, blockchain has been introduced as an effective solution to IoT applications trying to provide solutions to these challenges. In this paper, we introduce a new decentralized IoT application using blockchain technology, namely, ParkChain. The ParkChain application operates in a way that no one can delete, revert, hack, or question the time a registered vehicle securely entered a parking area. In order to evaluate ParkChain, we have implemented the smart contract on top of Ethereum Blockchain along with a traditional Image Processing / Computer Vision approach for License Plate Recognition and using a Raspberry Pi we control the access on a parking place. We report on several experiments that assess the performance of ParkChain application.
Z. Zinonos, P. Christodoulou, A. Andreou and S. A. Chatzichristofis, “PARKCHAIN: AN IOT PARKING SERVICE BASED ON BLOCKCHAIN”, «15th IEEE International Conference on Distributed Computing in Sensor Systems, DCOSS», pp. 687-693, 29-31 May 2019, Santorini, Greece