Patent ID: 11936777
Assignee: BEIJING UNIVERSITY OF POSTS AND TELECOMMUNICATIONS
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. A quantum key distribution (QKD) secured access network (QAN), comprising:
an optical line terminal (OLT);
a plurality of optical network units (ONUs);
a QKD receiver arranged at the OLT;
a QKD transmitter arranged at each of the ONUs;
a relay arranged at the QKD receiver; and
a key pool (KP) arranged at each ONU and the OLT; wherein,
the OLT is configured to
receive key requests from the plurality of ONUs; wherein, each key request comprises:

a source ONU of the key request, a destination ONU of the key request, quantity of secret-keys required, and level of a user request corresponding to the key request; wherein, the level of the user request comprises a high level and a low level;
determining, by the OLT, level of each key request according to the level of the user request corresponding to the key request and whether there is another key request whose source ONU is the destination ONU of the key request and whose destination ONU is the source ONU of the key request; wherein, determining the level of each key request comprises:
in response to determining the level of the user request corresponding to a first key request of the key requests is high level and there is a second key request who is high level and whose source ONU is the destination ONU of the first key request and whose destination ONU is the source ONU of the first key request, determining, by the OLT, levels of the first key request and the second key request are level 1, and forming, by the OLT, the first key request and the second key request as a key request pair;
in response to determining the level of the user request corresponding to a third key request of the key requests is high level and there is no key request whose source ONU is the destination ONU of the third key request and whose destination ONU is the source ONU of the third key request, determining, by the OLT, level of the third key request is level 2;
in response to determining the level of the user request corresponding to a fourth key request of the key requests is low level and there is a fifth key request whose source ONU is the destination ONU of the fourth key request and whose destination ONU is the source ONU of the fourth key request, determining, by the OLT, levels of the fourth key request and the fifth key request are level 3;
in response to determining the level of the user request corresponding to a sixth key request of the key requests is low level and there is no key request whose source ONU is the destination ONU of the sixth key request and whose destination ONU is the source ONU of the sixth key request, determining, by the OLT, level of the sixth key request is level 4;

obtain quantity of secret-keys to be provisioned for each key request according to the quantity of secret-keys required of the key request and quantity of secret-keys in the KP corresponding to the ONU which sends the key request;
generate an SKP queue according to the level of each key request and the quantity of secret-keys to be provisioned for each key request; wherein, the key requests in the SKP queue are sorted according to the level of each key request from high to low;

the OLT, the QKD receiver, two QKD transmitters corresponding to the source ONU and the destination ONU of the key request and the quantum relay are configured to generate at least one secret-key for each key request in the SKP queue according to a sequence of the SKP queue and the quantity of secret-keys to be provisioned for each key request;
the OLT is further configured to store the at least one secret-key in the KPs corresponding to the source ONU and the destination ONU;
in response to determining a secure communication between a source ONU and a destination ONU starts, the source ONU is configured to take a secret-key from the KP corresponding to the source ONU to encrypt the data; and the destination ONU is configured to take the secret-key from the KP corresponding to the destination ONU to decrypt the data encrypted.