Method, device and system for security authentication

The invention discloses a method, a device and a system for safety authentication, and relates to the technical field of information security. Authentication efficiency can be enhanced and resource cost can be reduced. The invention comprises that: a digital certificate and first user authentication information of a user are acquired; the digital certificate and the first user authentication information of the user are sent to an authentication service terminal; an authentication ticket and conversation secret key information which are sent by the service terminal are received; a conversation secret key is acquired from the conversation secret key information, and second user authentication information is generated according to the conversation secret key; an authentication credential is generated according to the received authentication ticket and the second user authentication information; and the authentication credential and a business request are sent to a business service terminal. The embodiment of the invention is mainly applied to authentication and authorization processes.