AV-Portal 3.23.2 (82e6d442014116effb30fa56eb6dcabdede8ee7f)

Security proof of the unbalanced phase-encoded BB84 protocol

Video in TIB AV-Portal: Security proof of the unbalanced phase-encoded BB84 protocol

Formal Metadata

Title
Security proof of the unbalanced phase-encoded BB84 protocol
Title of Series
Number of Parts
30
Author
Contributors
License
CC Attribution - NonCommercial - NoDerivatives 2.5 Switzerland:
You are free to use, copy, distribute and transmit the work or content in unchanged form for any legal and non-commercial purpose as long as the work is attributed to the author in the manner specified by the author or licensor.
Identifiers
Publisher
Release Date
2012
Language
English

Content Metadata

Subject Area
Abstract
In optical implementations of the phase-encoded BB84 protocol, the bit information is usually encoded in the phase of two consecutive photon pulses generated in a Mach-Zehnder interferometer. In the actual experimental realization, the loss in the arms of the Mach-Zehnder interferometer is not balanced, for example because only one arm contains a lossy phase modulator. Therefore, the amplitudes of the pulses is not balanced, and the structure of the signals and measurements no longer corresponds to the (balanced) ideal BB84 protocol. Hence, the BB84 security analysis no longer applies in this scenario. We provide a security proof of the unbalanced phase-encoded BB84. The resulting key rate turns out to be lower than the key rate of the ideal BB84 protocol. Therefore, in order to guarantee security, the loss due to the phase modulator cannot be ignored.
Feedback
hidden