Patent ID: 11863664
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A method of performing authority transfer in a storage device that includes a first storage region and is accessed by a plurality of user identifications (IDs), the method comprising:
performing a key exchange between a first user ID having a first access authority to the first storage region and a second user ID to be obtained the first access authority;
while the storage device is accessed by the first user ID, encrypting a first key-encryption-key (KEK) based on a ciphering key, the first KEK corresponding to the first access authority, the ciphering key being obtained by the key exchange; and
while the storage device is accessed by the second user ID, decrypting the encrypted first KEK based on the ciphering key, wherein performing the key exchange includes:
generating, by a trusted third party (TTP) in or coupled to the storage device, a first certificate for the first user ID based on the first user ID and a first public key;
generating, by the TTP, a second certificate for the second user ID based on the second user ID and a second public key;
while the storage device is accessed by the first user ID, performing a first verification on the second certificate based on a third certificate in or accessed by the TTP;
when the first verification is successfully completed, deriving the ciphering key based on a first private key and the second public key obtained by the first verification;
while the storage device is accessed by the second user ID, performing a second verification on the first certificate based on the third certificate; and
when the second verification is successfully completed, deriving the ciphering key based on a second private key and the first public key obtained by the second verification.