International Journal Of Application
(IEEE Xplore Abstract)
Heisenberg Uncertainty Theorem
BB84 Cryptography Protocol
What is Quantum Cryptography
• Quantum Cryptography is modern approach for
• Its based on physical laws.
• Two element of quantum mechanism :
a. Heisenberg uncertainty theorem
b. Principle of photon polarization
Keywords are : Quantum cryptography , Quantum key
distribution ,network security
• Quantum Cryptography was recommended by
Stephen Weisner in the early 1970.
• In 1984 first quantum cryptography protocol
Mechanism Of Quantum Cryptography
• Quantum cryptosystems depend on two important
components quantum mechanics –Heisenberg uncertainty
theorem and principle of photon polarization .Heisenberg
uncertainty principle states that , it is impossible to
determine quantum state and polarization states that it is
impossible to know about unknown qubits.
Quantum key distribution (QKDS)
Quantum information is stored as the state of atomic or
sub-atomic particles and qubit is an elementary unit of
quantum information .
Quantum Cryptography Protocols
• In 1984,Bennett and Brassard proposed first
quantum cryptographic protocol BB84.
• This work for transmission over fiber optics
cable and over free space.
• Another protocols are B92 cryptography
protocol , EPR cryptography protocol ,
Quantum teleportation etc.
• Most popular quantum key distribution is based on BB84
cryptography protocol .It’s depend on non-cloning theorem
of non-orthogonal quantum states.BB84 works as follows:-
1.sender (suppose Alice)sends out a series of single
photons. For each photon one of two possible base states ,
one having the possible polarization direction up/down
and left/right and another one is polarization with 45 .In
each case actual polarization direction is is also arbitary
• The receiver 2
• Receiver (Bob)detects polarization of photons with base
states so, half of photons will be detected with wrong
• Then Alice and Bob use a public communication channel
to talk about states used for each photons and choose
suitable base state photons.
• And reject all photons with wrong base states.
• Third party easy detectable .
• There is not need for complex mathematic
computation, so it increase computation
power so it is faster than traditional approach.