Patent ID: 8276185

Claim:
A method of allowing access to a memory device by an external device, the method including: receiving at the memory device an access request to a selected storage area by the external device; and performing an unlock procedure including: issuing a first code to the external device, the first code issued by the memory device; sending the first code to the external device; receiving, from the external device, a second code at the memory device, the second code being generated by a first encryption process performed on the first code to obtain the second code; at the memory device, temporarily unlocking the selected storage area to allow the external device to access the selected storage area more than once over a predetermined time interval based on the received second code, the temporarily unlocking including performing at least one second encryption process on the second code to obtain the first code; relocking the storage area after lapse of the predetermined time interval; changing the first code to a new value; and unlocking the storage area and granting the external device access to the storage area again for the predetermined time interval in response to verifying the validity of the received second code, as changed based on the new value of the first code.