Digital payment systems are an evolving field in present day with the recent enhancements in seamless digital currencies. Thus, despite the benefits of cryptocurrency based digital payments systems, their adoption and diffusion within general payment platform domain are significantly hindered. Blockchain architecture is widely recognized as a promising mechanism to support the management of cryptocurrency related transactions. However, ensuring the security of digital payment transactions is a challenging task due to various security threats and existing prevention mechanisms that are either computationally expensive or domain dependent. Among many, the Man-in-the-Middle attack and Double Spending are identified as key security vulnerabilities. The purpose of this study is to investigate the means of addressing the said security issues by proposing a feasible transaction verification methodology; targeting a common payment platform that integrates different vendor based digital currencies together. The currency miners and the user applications are identified as the core components that cooperate with transactions. Accordingly, a scenario based transaction verification model is designed by considering transaction patterns among miners and user applications. The bitcoin-similar concept of ‘trust network’ is adopted in verifying transactions via building a trusted network among currency miners in the payment platform using digital signatures along with SHA-256 hashing and RSA algorithm. In strengthening the verification level, an approach of acknowledgements is defined associated with a minimum required level of probability. Furthermore, a time constraint is set depending on the peer-to-peer network conditions for a particular transaction to get completed with proper verification. It is explored the strength and feasibility of the proposed methodology in the perspective of transaction verification over man-in-the-middle attack using a probabilistic evaluation where the possibility of a transaction getting verified decreases proportionally when the trusted network of miners getting unhealthy. Also, the double spending prevention is evaluated using the implementation of a mobile-based digital wallet as the proof-of-concept.

TITLE - Transaction Verification Model for Peer-to-Peer Service-Oriented Digital Currency Transactions Based on the Foundation of Blockchain Architecture
AUTHOR - Iresha Dilhani Rubasinghe
••••••IJSER Edition - February 2017

UNIVERSITY - University of Colombo School of Computing
GUIDE NAME -
Iresha
Dilhani
Rubasinghe