QKD Protocols
Alvina Ali
, Introduction
QKD is a secure communication method based on the laws of
quantum mechanics, which enables two parties, Alice and Bob, to
produce a shared random secret key in the presence of an
eavesdropper, Eve. Several protocols have been proposed and
experimentally realized over the course of years, starting from
BB84. Other protocols to be discussed today are
B92
SARG04
Decoy state
DPS
Orthogonal state.
, Review of BB84
Four polarization sates of a photon in two non-orthogonal
basis, say X and Z.
Alice randomly prepares and chooses between |±ix and |±iz .
Bob also measures randomly choosing between X or Z basis,
independently of Alice.
Sifted key is obtained after publicly discarding all bits where
basis of the two parties does not match.
Security is dependent on the the fact that Eve cannot get
deterministic results.
Alvina Ali
, Introduction
QKD is a secure communication method based on the laws of
quantum mechanics, which enables two parties, Alice and Bob, to
produce a shared random secret key in the presence of an
eavesdropper, Eve. Several protocols have been proposed and
experimentally realized over the course of years, starting from
BB84. Other protocols to be discussed today are
B92
SARG04
Decoy state
DPS
Orthogonal state.
, Review of BB84
Four polarization sates of a photon in two non-orthogonal
basis, say X and Z.
Alice randomly prepares and chooses between |±ix and |±iz .
Bob also measures randomly choosing between X or Z basis,
independently of Alice.
Sifted key is obtained after publicly discarding all bits where
basis of the two parties does not match.
Security is dependent on the the fact that Eve cannot get
deterministic results.
