Service provision method and apparatus for determining approval of multiple users and providing service

A service provision method, comprising the steps of:

• transmitting an electronic signature request message to a first terminal from among n terminals to receive a first electronic signature value generated in the first terminal from the first terminal and performing verification of the received first electronic signature value when a service execution request for executing a service is received from the first terminal;
• transmitting an electronic signature request message to terminals other than the first terminal from among the n terminals to receive electronic signature values respectively generated in the other terminals from the other terminals and performing verification of the electronic signature values received from the other terminals when verification of the first electronic signature value is completed;
• requesting any one of n secret keys and a message about approval or non-approval of the service execution for the n terminals when verification of the electronic signature values received from the other terminals is completed, the n secret keys being used to execute a service executable by the n terminals jointly;
• checking whether n secret keys received from the n terminals are consistent with n secret keys stored in a memory when secret keys and messages about approval or non-approval are received from all then terminals within a predetermined time;
• executing the service when the n secret keys received from the n terminals are consistent with the n secret keys stored in the memory and messages about approval of the service execution are received from all the n terminals;
• re-requesting the secret key and the message about approval or non-approval when the n secret keys received from the n terminals are not consistent with the n secret keys stored in the memory;
• and
• when at least one of the electronic signature value, the secret key value and the message about approval or non-approval is not received from at least one of the other terminals within the predetermined time, determining that the service execution request of the first terminal is approved.