Identity authentication method and authentication information acquisition method

The invention relates to the field of identity authentication and in particular relates to an identity authentication method and an authentication information acquisition method. The identity authentication method comprises the following steps: acquiring identity information of a person to be authenticated and to-be-authenticated biologic characteristic information, wherein the identity information corresponds to the to-be-authenticated biologic characteristic information; retrieving the authenticated biologic characteristic information which corresponds to the to-be-authenticated biologic characteristic information in a preset database according to the identity information; comparing the authenticated biologic characteristic information with the to-be-authenticated biologic characteristic information if the authenticated biologic characteristic information is retrieved so as to acquire a similarity value between the authenticated biologic characteristic information and the to-be-authenticated biologic characteristic information; allowing to pass identity authentication if the similarity value exceeds a preset threshold value. According to the identity authentication method provided by the invention, the authentication operation is performed by an operator by authenticating whether the to-be-authenticated biologic characteristic information and the preset authenticated biologic characteristic information are similar, and the identity authentication speed is improved through automatic similarity retrieval and comparison.