Disclosed herein are a hardware security module, a device having the hardware security module, and a method for operating the device. The method for verifying integrity of executable code in a device includes dividing, by a Micro-Control Unit (MCU), executable code into multiple blocks, generating, by the MCU, hash values corresponding to the blocks resulting from the division, storing, by a Hardware Security Module (HSM), the generated hash values, calculating, by the MCU, at least one hash value, among hash values of the multiple blocks when the executable code boots, and comparing, by the HSM, the calculated hash value with a hash value corresponding to the calculated hash value, among the hash values stored in the HSM.