Method and system for backing up private key of electronic signature token

A system for backing up a private key of an electronic signature token, comprising a first electronic signature token and a second electronic signature token, wherein the first electronic signature token comprises a first obtaining module, a first negotiation module, a first encrypting module, a first sending module, a first decrypting module and a fourth obtaining module, the second electronic signature token comprises a second obtaining module, a second negotiation module, a second decrypting module, a third obtaining module, a second encrypting module, and a second sending module,

• each of the first obtaining module and the second obtaining module is configured to obtain a first matching code;
• the first negotiation module and the second obtaining module are configured to negotiate using the first matching code, an encrypting strategy and a decrypting strategy corresponding to the encrypted strategy used for communication between the first electronic signature token and the second electronic signature token;
• the first encrypting module is configured to encrypt a private key backup request data packet using the encrypting strategy, in which the private key backup request data packet comprises matching code information;
• the first sending module is configured to send an encrypted private key backup request data packet;
• the second decrypting module is configured to decrypt the encrypted private key backup request data packet to obtain the private key backup request data packet, after receiving the encrypted private key backup request data packet;
• the third obtaining module is configured to obtain a second matching code from the matching code information in the private key backup request data packet, and to take the second matching code as a first pending verification code;
• the second encrypting module is configured to encrypt using the encrypting strategy a private key backup response data packet if the first pending verification code is identical with the first matching code obtained locally, in which the private key backup response data packet comprises the private key;
• the second sending module is configured to send an encrypted private key backup response data packet;
• the first decrypting module is configured to decrypt the encrypted private key backup response data packet using the decrypting strategy to obtain the private key backup response data packet, after obtaining the encrypted private key backup response data packet;
• and
• the fourth obtaining module is configured to obtain the private key from the private key backup response data packet.