Key distribution method and system

A key distribution system, comprising:

• a card issuer management platform which comprises:
• a generating module, configured to generate initial keys of a supplementary security domain corresponding to an application provider;
• an importing module, configured to import the initial keys and a root public key trusted for external authentication to the supplementary security domain;
• a first transmitting module, configured to transmit information of the supplementary security domain and the initial keys to an application provider management platform;
• the application provider management platform which comprises:
• a receiving module, configured to receive the information of the supplementary security domain and the initial keys of the card issuer management platform;
• a selecting module, configured to select the supplementary security domain of the intelligent card by a service terminal according to the information of the supplementary security domain and the initial keys;
• a generating module, configured to generate a public key and a private key of the supplementary security domain and a supplementary security domain certificate;
• a second transmitting module, configured to encrypt the public key and the private key as well as the supplementary security domain certificate, and then transmit them to the supplementary security domain, to complete the supplementary security domain key distribution;
• the service terminal, configured to establish communications with the intelligent card through a reading and writing device, and to establish a connection between the intelligent card and the application provider management platform;
• the intelligent card, located in a mobile terminal, and comprising the supplementary security domain, wherein the supplementary security domain being set according to the initial keys and the root public key trusted sent by the application provider management platform, and being set according to the public key and the private key as well as the supplementary security domain certificate sent by the application provider management platform, and installing the supplementary security domain certificate.