What is Quantum Cryptography and How it works.
                     What is Quantum 
Cryptography?
Working of 
Quantum 
Cryptography
What is Quantum 
Cryptography?
Cryptography is the process of encrypting 
data or converting plain text into 
scrambled text so that only someone who 
has the right “key” can read it. Quantum 
cryptography, by extension, simply uses 
the principles of quantum mechanics to 
encrypt data and transmit it in a way that 
cannot be hacked.
Source: quantumxc.com
Mechanics behind 
quantum 
Cryptography
The particles that make up the universe 
are inherently uncertain and can 
simultaneously exist in more than one 
place or more than one state of being.
Photons are generated randomly in one 
of two quantum states.
Source: quantumxc.com
How Quantum 
Cryptography Works?
Series of photons
Quantum cryptography, or quantum key 
distribution (QKD), uses a series of 
photons (light particles) to transmit data 
from one location to another over a fiber 
optic cable.
Source: quantumxc.com
Measurements of 
the properties
By comparing measurements of the 
properties of a fraction of these photons, 
the two endpoints can determine what 
the key is and if it is safe to use.
Source: quantumxc.com
Process 1
The sender transmits photons through a 
filter (or polarizer) which randomly gives 
them one of four possible polarizations 
and bit designations: Vertical (One bit), 
Horizontal (Zero bit), 45 degree right (One 
bit), or 45 degree left (Zero bit).
Source: quantumxc.com
Process 2
The photons travel to a receiver, which 
uses two beam splitters 
(horizontal/vertical and diagonal) to 
“read” the polarization of each photon. 
The receiver does not know which beam 
splitter to use for each photon and has 
to guess which one to use.
Source: quantumxc.com
Difference b/w post-
quantum cryptography 
and quantum 
cryptography?
Post-quantum cryptography refers to 
cryptographic algorithms that are 
thought to be secure against an attack 
by a quantum computer. 
However, quantum computers running 
Shor’s algorithm will be able to break 
math-based systems in moments.
Source: quantumxc.com
Why quantum 
cryptography is 
important?
The technology promises to make some 
kinds of computing problems much, 
much easier to solve than with today’s 
classical computers.
Source: quantumxc.com
Quantum vs 
Conventional 
Cryptography
Classical Cryptography comes with two 
main techniques: symmetric and 
asymmetric cryptography. However, 
these cryptography techniques face a 
threat from quantum algorithms.
Quantum cryptography offers the 
advantages of ‘unconditional security’ 
and sniffing detection. 
Source: quantumxc.com
Challenges
One of the main flaws in the range in 
which quantum cryptography can 
provide security. 
The reason why the length of quantum 
cryptology capability is short is because 
of interference.
Source: quantumxc.com