Packet-switching quantum key distribution

Patent metadata

Field	Value
Publication number	US-12238208-B2
Application number	US-202318175807-A
Country	US
Kind code	B2
Filing date	Feb 28, 2023
Priority date	Feb 28, 2023
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A network element in a quantum network receives a hybrid frame including a classical header and a quantum payload. The network element processes the classical header for a length of time and generates a new classical header. The network element drops a portion of the quantum payload based on the length of time spent processing the classical header and updates the hybrid frame to include the new classical header and the quantum payload without the dropped portion.

First claim

What is claimed is:

1. A method comprising:
receiving a hybrid frame at a router in a quantum network, the hybrid frame including a classical header and a quantum payload;
processing the classical header for a length of time;
generating a new classical header;
dropping a portion of the quantum payload based on the length of time spent processing the classical header; and
updating the hybrid frame to include the new classical header and the quantum payload without the dropped portion.

2. The method of claim 1 , further comprising responsive to a determination that the quantum payload exceeds a predetermined threshold, transmitting the hybrid frame to a next hop in the quantum network.

3. The method of claim 2 , wherein the predetermined threshold is based on the length of time spent processing the classical header.

4. The method of claim 2 , further comprising:
obtaining one or more traffic indications from other routers in the quantum network; and
estimating a total length of time for processing the classical header at a plurality of routers along a path in the quantum network between a source of the hybrid frame and a destination of the hybrid frame,
wherein the predetermined threshold is based on the total length of time estimated for processing the classical header.

5. The method of claim 2 , further comprising generating a Quantum Key Distribution (QKD) metric that quantifies a probability that the hybrid frame will generate a minimum number of secret bits at a destination of the hybrid frame, wherein the predetermined threshold is based on the QKD metric.

6. The method of claim 1 , wherein the portion dropped from the quantum payload includes an initial portion dropped from a beginning of the quantum payload.

7. The method of claim 1 , further comprising storing the quantum payload while the classical header is processed, wherein the portion dropped from the quantum payload includes a random portion based on losses from storing the quantum payload.

8. The method of claim 1 , further comprising:
determining that an output channel of the router is occupied; and
dropping an additional portion of the quantum payload based on a duration of time waiting for the output channel to be ready to transmit the hybrid frame.

9. An apparatus comprising:
a network interface configured to communicate with computing devices in a quantum network; and
a processor configured to:
receive a hybrid frame via the network interface, the hybrid frame including a classical header and a quantum payload;
process the classical header for a length of time;
generate a new classical header;
drop a portion of the quantum payload based on the length of time spent processing the classical header; and
update the hybrid frame to include the new classical header and the quantum payload without the dropped portion.

10. The apparatus of claim 9 , wherein the processor is further configured to cause the network interface to transmit the hybrid frame to a next hop in the quantum network, responsive to a determination that the quantum payload exceeds a predetermined threshold.

11. The apparatus of claim 10 , wherein the predetermined threshold is based on the length of time spent processing the classical header.

12. The apparatus of claim 10 , wherein the processor is further configured to:
obtain one or more traffic indications from other routers in the quantum network; and
estimate a total length of time for processing the classical header at a plurality of routers along a path in the quantum network between a source of the hybrid frame and a destination of the hybrid frame,
wherein the predetermined threshold is based on the total length of time estimated for processing the classical header.

13. The apparatus of claim 10 , wherein the processor is further configured to generate a Quantum Key Distribution (QKD) metric that quantifies a probability that the hybrid frame will generate a minimum number of secret bits at a destination of the hybrid frame, wherein the predetermined threshold is based on the QKD metric.

14. The apparatus of claim 9 , wherein the portion dropped from the quantum payload includes an initial portion dropped from a beginning of the quantum payload.

15. The apparatus of claim 9 , further comprising a quantum storage device configured to store the quantum payload while the classical header is processed, wherein the portion dropped from the quantum payload includes a random portion based on losses from storing the quantum payload.

16. A system comprising:
a plurality of routers in a quantum network, each router of the plurality of routers configured to:
receive a hybrid frame including a classical header and a quantum payload;
process the classical header for a length of time;
generate a new classical header;
drop a portion of the quantum payload based on the length of time spent processing the classical header; and
update the hybrid frame to include the new classical header and the quantum payload without the dropped portion.

17. The system of claim 16 , wherein each router is further configured to transmit the hybrid frame to a next hop in the quantum network, responsive to a determination that the quantum payload exceeds a predetermined threshold.

18. The system of claim 17 , wherein the predetermined threshold is based on the length of time spent processing the classical header.

19. The system of claim 17 , wherein each router is further configured to:
obtain one or more traffic indications from other routers in the quantum network; and
estimate a total length of time for processing the classical header at a set of routers among the plurality of routers along a path in the quantum network between a source of the hybrid frame and a destination of the hybrid frame,
wherein the predetermined threshold is based on the total length of time estimated for processing the classical header.

20. The system of claim 17 , wherein each router is further configured to generate a Quantum Key Distribution (QKD) metric that quantifies a probability that the hybrid frame will generate a minimum number of secret bits at a destination of the hybrid frame, wherein the predetermined threshold is based on the QKD metric.

Assignees

• Cisco Tech Inc

Inventors

• Diadamo Stephen Magno
• Shabani Alireza
• Qi Bing
• Mandil Reem M

Classifications

• H04L9/0858

  Details about key distillation or coding, e.g. reconciliation, error correction, privacy amplification, polarisation coding or phase coding · CPC title

• H04L9/0855 Primary

  involving additional nodes, e.g. quantum relays, repeaters, intermediate nodes or remote nodes · CPC title