Authentication in the field of biometric technolgy; Authentication, issuance and validation of digital certificates; Computer security services in the nature of providing authentication, issuance, validation and revocation of digital certificates; Electronic signature verification services using technology to authenticate user identity; Providing user authentication services using biometric hardware and software technology for e-commerce transactions; Providing user authentication services using biometric hardware and software technology for access control; Providing user authentication services using blockchain-based software technology for cryptocurrency transactions; Providing user authentication services using single sign-on technology for online software applications; Providing user authentication services using cameras for e-commerce transactions; User authentication services using blockchain technology for login and sign ups; User authentication services using single sign-on technology for online software applications; User authentication services using technology for e-commerce transactions