Battery Pack and Electronic Apparatus

Abstract

A battery pack includes at least one rechargeable battery configured to output power; a remaining battery capacity detection unit configured to detect a remaining battery capacity of the at least one rechargeable battery; and a cryptographic unit configured to output a response word in response to an external request word by encrypting the external request word based on a cryptographic algorithm with a common code key.

1 . A battery pack comprising:
 at least one rechargeable battery configured to output power;   a remaining battery capacity detection unit configured to detect a remaining battery capacity of the at least one rechargeable battery; and   a cryptographic unit configured to output a response word in response to an external request word by encrypting the external request word based on a cryptographic algorithm with a common code key.   
   
   
       2 . The battery pack as claimed in  claim 1 , wherein:
 the battery pack outputs power to an electronic apparatus,   the external request word is input from the electronic apparatus, and   the cryptographic algorithm and the common code key are identical to those used by an authentication unit of the electronic apparatus.   
   
   
       3 . The battery pack as claimed in  claim 1 , wherein the cryptographic unit comprises:
 a reception unit configured to receive the external request word;   an encryption unit configured to encrypt the external request word received by the reception unit; and   a transmission unit configured to output the response word generated by the encryption unit.   
   
   
       4 . The battery pack as claimed in  claim 1 , further comprising:
 a nonvolatile memory configured to store the common code key.   
   
   
       5 . The battery pack as claimed in  claim 4 , wherein the common code key is renewed by a new common code key received from an electronic apparatus to which the battery pack is detachably connected. 
   
   
       6 . The battery pack as claimed in  claim 1 , wherein the remaining battery capacity detection unit includes the cryptographic unit as software. 
   
   
       7 . The battery pack as claimed in  claim 1 , wherein the remaining battery capacity detection unit includes the cryptographic unit as hardware. 
   
   
       8 . An electronic apparatus comprising:
 a transmission unit configured to output a request word in response to external power;   a reception unit configured to receive an external response word;   an encryption unit configured to encrypt the request word based on a cryptographic algorithm with a common code key; and   an authentication unit configured to collate the encrypted request word which has been encrypted by the encryption unit and the external response word.   
   
   
       9 . The electronic apparatus as claimed in  claim 8 , wherein
 the external power and the external response word are input from a battery pack which is detachably connected to the electronic apparatus,   the battery pack generates the external response word using the cryptographic algorithm and the common code key identical to those used by the encryption unit, and the electronic apparatus determines that the battery pack is an authenticated battery pack when the external response word and the encrypted request word collated by the authentication unit match.   
   
   
       10 . The electronic apparatus as claimed in  claim 8 , wherein the authentication unit comprises:
 a transmission unit configured to output the request word to a battery pack which is detachably connected to the electronic apparatus;   a reception unit configured to receive the external response word from the battery pack; and   a collation unit configured to collate the external response word and the encrypted request word;   wherein the battery pack generates the external response word using the cryptographic algorithm and the common code key identical to those used by the encryption unit, and the electronic apparatus determines that the battery pack is an authenticated battery pack when the external response word and the encrypted request word collated by the collation unit match.   
   
   
       11 . The electronic apparatus as claimed in  claim 8 , wherein the authentication unit comprises
 a transmission unit configured to output the request word to a battery pack which is detachably connected to the electronic apparatus;   a reception unit configured to receive the external response word from the battery pack;   a decryption unit configured to decrypt the external response word based on the cryptographic algorithm and the common code key identical to those used by the battery pack; and   a collation unit configured to collate the decrypted external response word which has been decrypted by the decryption unit from the external response word and the request word;   wherein the battery pack generates the external response word using the cryptographic algorithm and the common code key identical to those used by the encryption unit, and the electronic apparatus determines that the battery pack is an authenticated battery pack when the decrypted external response word and the request word collated by the collation unit match.   
   
   
       12 . The electronic apparatus as claimed in  claim 8 , wherein the electronic apparatus determines that the battery pack being connected is unauthenticated when the electronic apparatus does not receive the response word from the battery pack. 
   
   
       13 . The electronic apparatus as claimed in  claim 12 , further comprising:
 an operation restriction unit; and   a display unit;   wherein the operation restriction unit prohibits operation or restricts the operation or part of the operation of the electronic apparatus, and the display unit displays that the operations or part of the operations of the electronic apparatus is prohibited or restricted, when the electronic apparatus determines that the battery pack is unauthenticated.