Key distribution method and authentication server

An authentication server distributing a key for encrypting and decrypting data in accordance with providing a service, the authentication server being connected with wireless terminals through a communication network, the authentication server comprising:

• a communication unit configured to receive encrypted characteristic information from each of the wireless terminals;
• a decryption module configured to decrypt the encrypted characteristic information and obtain each characteristic information;
• and
• a generator configured to generate a random key and a group key, and to generate a distribution key by use of the generated random key, the group key and the characteristic information,
• wherein the distribution key is transmitted to each wireless terminal through the communication unit.

A recording medium tangibly embodying a program of instructions executable by a digital processing apparatus for executing a method of generating and distributing a key for encrypting and decrypting data in accordance with providing a service, the program being readable by the digital processing apparatus, the program configured to:

• obtain characteristic information by decrypting encrypted characteristic information received from each of n number of wireless terminals;
• generate a random key;
• generate a group key configured to be used for encrypting and decrypting data in accordance with providing a service;
• generate a distribution key by using the random key, the group key and the characteristic information;
• and
• transmitting the distribution key to each wireless terminal.