The development and urbanization occurred in past decades led to the concept of smart cities. These smart cities consist of various high-risk locations, so there is a need of smart authentication technique which is more reliable and secured. We proposed smart security framework with the integration of enhanced existing technologies. This authentication framework provides security for the high-risk location, such as government office buildings, airport, military bases, and space stations. The area consists of various Wi-fi access points creating the geo-fence. As soon as the person enters into the geo-fence with his smartphone, biometric authentication is carried out using smartphone and accordingly the person is allowed to enter inside the geo-fence. At the same time, Wi-fi positioning system locates the path of person in the geo-fence. Biometric authentication uses the local binary pattern matching algorithm having accuracy of 80 %. The location of the person inside the geo-fence is tracked with the help of Trilateration method. The Wi-fi positioning system based on Trilateration method finds the location of the person with an error rate of 5 m, which is relatively very lower than the Global Positioning System. This wireless authentication framework provides the better solution for security of smart cities which in turn will be beneficial for maintaining the peaceful and healthy social relations. © Springer Science+Business Media Singapore 2016.