Card-less transactions, using mobile phones for financial operations, have surged in popularity. Researchers seek secure PIN authentication solutions. The ATM custodian method enables users to scan a QR code for co-location proof and a one-time PIN, reducing device load and offloading computation to the cloud. Users log in with a username and password, then scan the ATM’s QR code with their Android device. Instead of a fixed PIN, the card-less ATM generates a random OTP on the mobile device for authorized users. This OTP is entered on the ATM screen to initiate transactions, ensuring high security. The OTP is stored in the database and compared to the entered OTP for transaction approval. This system is user-friendly and reduces the risk of shoulder surfing.

• ATM Authentication
• Card-less Transactions
• One-time PIN (OTP) Security