A storage device comprising: a boot Read Only Memory , hereinafter referred to as ROM, configured to store a plurality of public keys and a boot ROM image ; an One-Time Programmable Memory , hereinafter referred to as OTP memory configured to identify a first public key among the plurality of public keys ; a first memory including a first area configured to store the plurality of public keys and a flash boot image different from the boot ROM image , and a second area configured to store a first boot signature corresponding to the flash boot image ; a second memory including a user data area , and a firmware image area configured to store a first firmware image including a first firmware signature ; and a memory controller configured to: receive a second firmware image including a second firmware signature different from the first firmware signature and a second boot signature different from the first boot signature , receive, from the first area of the first memory based on the second firmware image being received, a second public key among the plurality of public keys and the flash boot image , write the second boot signature in the second area of the first memory ; write the second firmware image in the firmware image area , and revoke the first public key in response to the reception of the second firmware image. a boot Read Only Memory , hereinafter referred to as ROM, configured to store a plurality of public keys and a boot ROM image ; an One-Time Programmable Memory , hereinafter referred to as OTP memory configured to identify a first public key among the plurality of public keys ; a first memory including a first area configured to store the plurality of public keys and a flash boot image different from the boot ROM image , and a second area configured to store a first boot signature corresponding to the flash boot image ; a second memory including a user data area , and a firmware image area configured to store a first firmware image including a first firmware signature ; and a memory controller configured to: receive a second firmware image including a second firmware signature different from the first firmware signature and a second boot signature different from the first boot signature , receive, from the first area of the first memory based on the second firmware image being received, a second public key among the plurality of public keys and the flash boot image , write the second boot signature in the second area of the first memory ; write the second firmware image in the firmware image area , and revoke the first public key in response to the reception of the second firmware image. receive a second firmware image including a second firmware signature different from the first firmware signature and a second boot signature different from the first boot signature , receive, from the first area of the first memory based on the second firmware image being received, a second public key among the plurality of public keys and the flash boot image , write the second boot signature in the second area of the first memory ; write the second firmware image in the firmware image area , and revoke the first public key in response to the reception of the second firmware image. <EOS>