AUTHENTICATE

1. To establish, usually by challenge and response , that a transmission attempt is authorized and valid. 2. Verify the identity of a user , user device, or other entity, or the integrity of data stored, transmitted, or otherwise exposed to unauthorized modification in an automated information system , or establish the validity of a transmitted message . [ NIS ] 3. A challenge given by voice or electrical means to attest to the authenticity of a message or transmission. [ JP1 ]