Design and Implementation of a Secure IPSec-GRE Virtual Private Network Framework for Remote Banking Communications

Abstract

The increasing adoption of digital banking services and remote connectivity has heightened the demand for secure, reliable, and resilient communication infrastructures within the financial sector. Financial institutions require network solutions that safeguard sensitive information exchanged among headquarters, branch offices, and remote users against unauthorised access, interception, and other cyber threats. Conventional networking approaches often face limitations in security, scalability, and fault tolerance, creating the need for more robust Virtual Private Network (VPN) architectures. This study presents the design and implementation of a secure VPN framework that integrates Internet Protocol Security (IPSec), Generic Routing Encapsulation (GRE), and the Open Shortest Path First (OSPF) routing protocol to facilitate secure and efficient communication across geographically distributed banking networks. The framework was modelled using Unified Modelling Language (UML) and implemented in Cisco Packet Tracer to simulate connectivity between a bank's headquarters, two branch offices, and remote users. To ensure the confidentiality, integrity, and authenticity of transmitted information, the system employed Advanced Encryption Standard (AES-256) encryption, Secure Hash Algorithm (SHA-256) hashing, and Authentication, Authorisation, and Accounting (AAA) services. Dynamic routing was achieved through OSPF, enabling rapid route optimisation and automatic recovery during network failures. Performance evaluation demonstrated the effectiveness of the proposed framework. The implementation achieved a 100% VPN tunnel establishment success rate, an average network latency of 3.4ms, throughput stability of approximately 98%, and zero packet loss during the transmission of 1,000 data packets. In addition, OSPF restored network connectivity in less than two seconds following simulated link failures, ensuring uninterrupted communication among all network nodes. The findings indicate that the integration of IPSec, GRE, and OSPF provides a secure, scalable, and resilient VPN solution capable of supporting inter-branch and remote banking communications. The proposed framework strengthens data confidentiality, improves network availability, and enhances communication reliability while providing a practical and cost-effective approach for secure remote access and business continuity in modern banking environments.