모바일 환경에서 한글 자모 혼합 패스워드가 가능한 보안 키패드 설계 = Design of a Secure Keypad Scheme for Passwords based on the Hangul Jamo in a Mobile Environment

다국어 초록 (Multilingual Abstract)

Currently, users utilize smartphones to perform authentication for personalized services and financial transactions. During the biometric authentication process via mobile sensors, secondary authentication such as a PIN is often required due to potential recog-nition failures or false acceptance. However, PIN authentication—consisting only of digits—possesses a limited key space, making it highly vulnerable to shoulder-surfing and brute-force attacks. Furthermore, secure passwords that include alphanumeric characters are typically based on the English alphabet, which poses difficulties for users who are not familiar with English or the QWERTY keyboard layout. This study proposes a novel approach to password authentication that enables the input of Hangul Jamo. Rather than the conventional approach of simply co-labeling Hangul Jamo on English keypads, the proposed technique leverages native Hangul input systems—such as ‘Cheonjiin’ or ‘Naratgul’—to provide an authentication solution that is highly intuitive and easy for domestic users to memorize. The proposed method ensures high security by providing a significantly larger key space that is robust against rainbow table attacks while offering enhanced convenience to Korean users. Moreover, it is highly resistant to social engineering attacks, as it employs a mechanism that makes password patterns difficult to discern.