An electronic apparatus is disclosed. The electronic apparatus includes: a communication interface comprising communication circuitry, and a processor configured to: identify strength of a signal received from an external device through the communication interface, based on the strength of the identified signal being greater than or equal to a threshold value, unlock authorization restriction on the electronic apparatus, wherein the processor is further configured to: based on the strength of the identified signal being less than the threshold value, maintain the authorization restriction, and based on authentication of the electronic apparatus being completed after the signal is received, adjust the threshold value based on strength of at least one signal received from the external device before the signal is received.