THE HUMAN FIREWALL: Why Nigerian Organisations Lose Millions to Social Engineering Despite Technical Security

Despite significant investments in firewalls, endpoint protection, and encryption, Nigerian organisations continue to lose billions of naira annually to social engineering attacks,  a threat vector that bypasses technology entirely by targeting human psychology. This paper examines why technical cybersecurity infrastructure alone is insufficient to protect Nigerian organisations against phishing, vishing, Business Email Compromise (BEC), pretexting, and AI-generated voice cloning attacks. Drawing on documented Nigerian case studies from 2024 to 2026, including the compromise of state governors' WhatsApp accounts and the May 2026 Tinubu deepfake voice note incident. The paper identifies the specific cultural, economic, and institutional factors that make Nigerian employees and organisations disproportionately vulnerable to social engineering. The paper proposes the Human Firewall Framework (HFF), a four-pillar model comprising continuous behavioural security training, institutional security culture development, process-level social engineering resistance, and AI-aware deepfake preparedness. Policy recommendations are directed at the CBN, NCC, NITDA, and Nigeria's private sector financial institutions.