Method, apparatus, and system for quantum key distribution, privacy amplification, and data transmission

• US 10,389,525 B2
• Filed: 10/30/2015
• Issued: 08/20/2019
• Est. Priority Date: 10/30/2014
• Status: Active Grant

• Current Assignee: Alibaba Group Holding Ltd.
• Original Assignee: Alibaba Group Holding Ltd.
• Inventors: Fu, Yingfang, Liu, Shuanlin, Gao, Yabin, Xiao, Li, Pang, Junying, Chen, Xiuzhong, Feng, Liang
• Primary Examiner(s): Zand, Kambiz
• Assistant Examiner(s): Kaplan, Benajmin A
• Application Number:
  US14/929,072
• Publication Number:
  US 20160149700A1
• Time in Patent Office: 1,390 Days
• Field of Search: 380278
• CPC Class Codes: H04L 9/0852 Quantum cryptography transmission systems employing electromagnetic waves other than radio waves, e.g. light, infrared H04B10/00; wavelength-division multiplex systems H04J14/02; WDM arrangements H04J14/03
• CPC Class Codes: H04L 9/0858 Details about key distillation or coding, e.g. reconciliation, error correction, privacy amplification, polarisation coding or phase coding

Abstract

A method and apparatus for quantum key distribution comprised of a privacy amplification method and device for the quantum key distribution process as well as a data transmission method and system based on quantum keys is provided, wherein the quantum key distribution method includes the following process: obtaining a bit stream of the same basis vector by sending or receiving coding quantum states of random bit streams and comparing those measurements obtained with the measurement basis vector; in accordance with a preset manner, extracting parameter information associated with privacy amplification and initial key information from the bit stream of the same basis vector after error correction; and using the initial key as an input to implement the privacy amplification algorithm based on the parameter information and thereby obtain shared quantum keys. Utilization of the method detailed herein can eliminate security risks in the negotiation of privacy amplification parameters in the alternative channel and effectively improve the security of quantum key distribution processes.

Claims

1. A method of quantum key distribution, the method comprising:

receiving a plurality of quantum states from a quantum channel;

extracting a binary bit stream from the plurality of quantum states;

modifying the binary bit stream to form a modified bit stream;

determining a required level of security;

determining a privacy amplification algorithm based on the required level of security;

extracting an initial key and a number of parameter values of a corresponding number of algorithm parameters required by the privacy amplification algorithm from the modified bit stream, the number of privacy amplification parameters being transmitted in an anonymous way; and

executing the privacy amplification algorithm based on the initial key and the parameter values to obtain a shared key.

2. The method of claim 1, further comprising wherein extracting the binary bit stream from the plurality of quantum states includes:

generating a string of receiver random bases;

measuring the plurality of quantum states with the string of receiver random bases to generate a string of measured bits that corresponds with the string of receiver random bases such that each measured bit has a corresponding receiver random basis;

receiving a string of transmitter random bases that corresponds with the string of receiver random bases;

comparing the receiver random basis of each bit in the string of measured bits with a corresponding transmitter random basis; and

discarding each bit in the string of measured bits where the receiver random basis fails to match the corresponding transmitter random basis to generate the binary bit stream.

3. The method of claim 1, wherein modifying the binary bit stream to form the modified bit stream includes:

selecting a first string of bits from the binary bit stream;

determining an error rate based on the first string of bits; and

determining if the error rate exceeds a threshold.

4. The method of claim 3, wherein determining the error rate based on the first number of bits includes:

transmitting the first string of bits;

receiving a transmitter string of bits, the transmitter string of bits corresponding with the first string of bits; and

determining the error rate based on differences between the first string of bits and the transmitter string of bits.

5. The method of claim 4, wherein determining the required level of security includes receiving a security level selection.

6. The method of claim 5, wherein the transmitter string of bits and the security level selection are received from a classical channel.

7. The method of claim 5, wherein determining the required level of security further includes determining a risk value based on the error rate.

8. The method of claim 7, wherein determining the required level of security further includes generating a weighted summation of the bit error rate, the risk value, and the security level selection.

9. The method of claim 3, wherein modifying the binary bit stream to form the modified bit stream further includes:

discarding the binary bit stream when the error rate exceeds the threshold; and

discarding the first string of bits when the error rate lies below the threshold to leave a second string of bits from the binary bit stream.

10. The method of claim 9, wherein modifying the binary bit stream to form the modified bit stream further includes error correcting the second string of bits to generate the modified bit stream.

11. The method of claim 1, wherein the privacy amplification algorithm includes a shift algorithm.

12. The method of claim 11, wherein the algorithm parameters include key length, key shift algorithm number, key shift direction, and key shift number.

13. The method of claim 1, wherein the privacy amplification algorithm includes a hash algorithm.

14. The method of claim 13, wherein the algorithm parameters include key length, number of binary bits per hash function coefficient, interception position from initial keys, and hash function serial number or hash function degree and coefficients.

15. An apparatus for quantum key distribution, the apparatus comprising:

a memory; and

a processor coupled to the memory, the processor to;

receive a plurality of quantum states from a quantum channel;

extract a binary bit stream from the plurality of quantum states;

modify the binary bit stream to form a modified bit stream;

determine a required level of security;

determine a privacy amplification algorithm based on the required level of security;

extract an initial key and a number of parameter values of a corresponding number of algorithm parameters required by the privacy amplification algorithm from the modified bit stream, the number of privacy amplification parameters being transmitted in an anonymous way; and

execute the privacy amplification algorithm based on the initial key and the parameter values to obtain a shared key.

16. The apparatus of claim 15, wherein to extract the binary bit stream from the plurality of quantum states the processor to further:

generate a string of receiver random bases;

measure the plurality of quantum states with the string of receiver random bases to generate a string of measured bits that corresponds with the string of receiver random bases such that each measured bit has a corresponding receiver random basis;

receive a string of transmitter random bases that corresponds with the string of receiver random bases;

compare the receiver random basis of each bit in the string of measured bits with a corresponding transmitter random basis; and

discard each bit in the string of measured bits where the receiver random basis fails to match the corresponding transmitter random basis to generate the binary bit stream.

17. The apparatus of claim 15, wherein to modify the binary bit stream to form the modified bit stream, the processor to further:

select a first string of bits from the binary bit stream;

determine an error rate based on the first string of bits; and

determine if the error rate exceeds a threshold.

18. The apparatus of claim 17, wherein to determine the error rate based on the first number of bits includes:

transmitting the first string of bits;

receiving a transmitter string of bits, the transmitter string of bits corresponding with the first string of bits; and

determining the error rate based on differences between the first string of bits and the transmitter string of bits.

19. The apparatus of claim 17, wherein to further modify the binary bit stream to form the modified bit stream, the process to further:

discard the binary bit stream when the error rate exceeds the threshold; and

discard the first string of bits when the error rate lies below the threshold to leave a second string of bits from the binary bit stream.

20. The apparatus of claim 19, wherein to further modify the binary bit stream to form the modified bit stream, the processor to further error correct the second string of bits to generate the modified bit stream.

21. The apparatus of claim 15, wherein the privacy amplification algorithm includes a shift algorithm.

22. The apparatus of claim 21, wherein the transmitter string of bits and the security level selection are received from a classical channel.

23. The apparatus of claim 21, wherein to determine the required level of security, the processor to further determine a risk value based on the error rate.

24. The apparatus of claim 23, wherein to determine the required level of security, the processor to further generate a weighted summation of the bit error rate, the risk value, and the security level selection.

25. The apparatus of claim 15, wherein the privacy amplification algorithm includes a hash algorithm.

26. The apparatus of claim 25, wherein the algorithm parameters include key length, number of binary bits per each hash function coefficient, interception position from initial keys, and hash function serial number, or hash function degree and coefficients.

27. The apparatus of claim 26, wherein the algorithm parameters include key length, key shift algorithm number, key shift direction, and shift number.

28. A non-transitory computer-readable storage medium having embedded therein program instructions, when executed by one or more processors of a computer, causes the computer to execute a method for distributing a quantum key, the method comprising:

receiving a plurality of quantum states from a quantum channel;

extracting a binary bit stream from the plurality of quantum states;

modifying the binary bit stream to form a modified bit stream;

determining a required level of security;

determining a privacy amplification algorithm based on the required level of security;

extracting an initial key and a number of parameter values of a number of corresponding algorithm parameters required by the privacy amplification algorithm from the modified bit stream, the number of privacy amplification parameters being transmitted in an anonymous way; and

executing the privacy amplification algorithm based on the initial key and the parameter values to obtain a shared key.

29. The medium of claim 28, wherein the privacy amplification algorithm includes a hash algorithm.

30. The medium of claim 29, wherein the algorithm parameters include key length, number of binary bits per hash function coefficient, interception position from initial keys, and hash function serial number or hash function degree and coefficients.

31. The medium of claim 28, wherein the privacy amplification algorithm includes a shift algorithm.

32. The medium of claim 31, wherein the algorithm parameters include key length, key shift algorithm number, key shift direction, and key shift number.

33. The medium of claim 28, wherein determining the required level of security includes receiving a security level selection.

34. The medium of claim 33, wherein determining the required level of security further includes determining a risk value based on the error rate.

35. The medium of claim 34, wherein determining the required level of security further includes generating a weighted summation of the bit error rate, the risk value, and the security level selection.

36. A method for distributing quantum keys, the method comprising:

transmitting, with a transmitter, a plurality of quantum states onto a quantum channel;

receiving, with a receiver, the plurality of quantum states from the quantum channel;

extracting, with the receiver, a binary bit stream from the plurality of quantum states;

modifying, with the receiver, the binary bit stream to form a modified bit stream;

determining, with the receiver, a required level of security;

determining, with the receiver, a privacy amplification algorithm based on the required level of security;

extracting, with the receiver, an initial key and a number of parameter values of a corresponding number of algorithm parameters required by the privacy amplification algorithm from the modified bit stream, the number of privacy amplification parameters being transmitted in an anonymous way; and

executing, with the receiver, the privacy amplification algorithm based on the initial key and the number of parameter values to obtain a shared key.

37. The method of claim 36, the method further comprising:

determining, with the transmitter, the required level of security; and

determining, with the transmitter, the privacy amplification algorithm based on the required level of security.

38. The method of claim 37, further comprising determining, with the transmitter, the number of algorithm parameters required by the privacy amplification algorithm.

39. The method of claim 38, further comprising generating an output bit string that includes a parameter bit string and a random key bit string, the parameter bit string including the number of algorithm parameters.

40. The method of claim 39, further comprising executing the privacy amplification algorithm based on the output bit string and the number of parameters to generate a transmitter bit string.

41. The method of claim 40, further comprising transmitting, with the transmitter, the transmitter bit string with a string of transmitter random bases as the plurality of quantum states.

42. The method of claim 37, further comprising transmitting, with the transmitter, the required level of service across a classical channel to the receiver.