Storage device, protection method, and electronic device

A method of protecting a storage device configured to encrypt data with an encryption key, to store the data in a storage area and to decrypt the data stored in the storage area with the encryption key, the method comprising:

• start counting triggered by turning on of the storage device;
• receiving a command that contains a password and time information from a host device connected to the storage device, the time information indicating current date and time measured by the host device;
• calculating elapsed time from last command input to current command input based on the time information contained in the command and a counter value counted until the command is received;
• adding the elapsed time calculated at the calculating to time information contained in a last command received last time;
• determining consistency of the time information contained in the current command based on a temporal relationship between a result of addition at the adding and the time information;
• disabling the encryption key if the time information is determined to be not consistent;
• and
• authenticating the password contained in the current command if the time information is determined to be consistent, and allowing access to the storage area if the password is successfully authenticated.

An electronic device comprising:

• a storage device configured to encrypt data with an encryption key, to store the data in a storage area and to decrypt the data stored in the storage area with the encryption key;
• a timer configured to generate time information indicating current date and time;
• and
• a transmitter configured to transmit a command containing a predetermined password and the time information to the storage device to access the storage device, wherein
• the storage device comprises
• an elapsed time counter configured to start counting triggered by turning on of the storage device;
• a receiver configured to receive the command from the transmitter;
• a calculator configured to calculate elapsed time from last command input to current command input based on the time information contained in the command and a counter value counted by the elapsed time counter until the command is received;
• an adder configured to add the elapsed time calculated by the calculator to time information contained in a last command received last time;
• a time information determination module configured to determine consistency of the time information contained in the current command based on a temporal relationship between a result of addition by the adder and the time information;
• a disabling module configured to disable the encryption key if the time information determination module determines that the time information is not consistent;
• and
• an authentication module configured to authenticate the password contained in the current command if the time information determination module determines that the time information is consistent, and allow access to the storage area if the password is successfully authenticated.