The debit card security breach blew big time last month. The trigger was fraudulent transactions in which debit cards were used in China and the US when cardholders were residing in India. The problem was not isolated to a single bank but several banks, both private and public sector banks. The banks complained to the National Payments Corporation of India (NPCI), which has oversight over retail payments systems in India. The probe by NPCI found a malware induced security breach in the systems of Hitachi Payment Services, which provides ATMs, point of sale and other services.