Authentication in the field of messenging; Authentication of data in the field of messenging using blockchain technology; Authentication, issuance and validation of digital certificates; Computer security services in the nature of providing authentication, issuance, validation and revocation of digital certificates; Electronic document and e-mail authentication services; Providing user authentication services using biometric hardware and software technology for e-commerce transactions; Providing user authentication services using single sign-on technology for online software applications; User authentication services using single sign-on technology for online software applications; User authentication services using technology for e-commerce transactions
Computer and Scientific