Diverse kind of attack using the vulnerability of user authentication on Internet service is announced recently. Especially, security accidents on the Internet banking service and Internet telephony service(SIP) are increased rapidly. Attack skills are also evolved into intelligent mechanism. Therefore, more enhanced authentication mechanism is required on existing Internet banking and telephone services for preventing those kinds of attacks using personal identity information such as biometric data. In this research, the proposed B-OTP mechanism can be used to enhance security on a user authentication procedure by combining biometric data with existing OTP mechanism. As a result, the security on internet banking and Internet telephone service will be more improved by using proposed B-OTP mechanism.