According to an embodiment of the present disclosure, an electronic device comprises a communication module, a memory storing a first seed for generating a one-time password (OTP), a character set and a first unique code assigned to a first user, and a processor, wherein the processor is configured to generate a first OTP using the first seed, generate a first sub code by mapping an operation result of the first unique code and the first OTP to the character set, generate a second sub code by mapping the first OTP to the character set, generate a code using the first sub code and the second sub code, and transmit the generated code to another electronic device through the communication module.