### Quantum Cryptography Introduction

Every time you buy something online, you put your trust in the simple mathematics of mathematics which is easy to do in one direction but it is difficult to do in contrast. This is what protects your credit card information from thieves. But the system can be hacked. For example, a popular encryption scheme can be undone by unlocking “key” encoded information, in two major numbers, only by making a large random number factor. It is an act that is exceptionally difficult today, but not impossible. With enough computing power, a detective government can break the key. Or some clever mathematician can find a simple way of doing this in a large number of factors and in theory, tomorrow. In search of more security than code breaker, a new generation of code makers is changing from math to physics. Experts from atoms and other particles, these cryptologists want to take advantage of the quantum mechanics rules that are adequately accurate to send messages. They are architects of a new field called Quantum Cryptography, which are of the same age in the last few decades. Quantum cryptography pulls its strength on the small-scale reality. The particles that make up our universe are naturally uncertain creatures, which exist in more than one place or more than one state. They behave only when they enter anything else or when we measure their properties.

### What Is Quantum Cryptography?

Quantum cryptography uses our current knowledge of physics to develop a cryptosystem that is not able to defeat, which is completely safe against the compromise without the recipient of the sender or messages. The term Quantum itself refers to the most fundamental behaviour of the smallest particle of matter and energy: Quantum theory tells all the things present and nothing can be done to violate it. Quantum cryptography, also called quantum encryption, enforces the principles of quantum mechanics to encrypt messages so that it can never be read by any person outside the desired recipient. It leverages several states of quantum, in which there is no “no change principle”, which means that it can not be inadvertently interrupted. Encryption has been since the beginning of time, the Assyrians have saved the Germans who protect military secrets with Enigma to protect their business secrets to the production of pottery. Today, it is in danger more than ever before. This is the reason why some people are looking for quantum cryptography to protect the data in the future. Quantum cryptography is not a new algorithm for encrypting and decrypting data. Instead, it is a technique to use a photon to generate a cryptographic key and transmit it to the receiver using a suitable communication channel. The most important role in cryptography is the cryptographic-key; It is used to encrypt/decrypt data. Quantum cryptography is different from the traditional cryptographic system in which it relies on physics rather than mathematics, as a key aspect of its security model.

### Quantum Cryptography Working

Quantum cryptography, in principle, can allow you to encrypt a message in such a way that it is never read by any person outside the intended recipient. Quantum cryptography is defined as “the science of exploiting quantum mechanical properties for performing cryptographic functions”, and the definition of common man is that in many states of quantum it has its “no change theory” This does not mean that it can not be inadvertently interrupted. Symmetric key cryptography is also known as secret key cryptography (SKC), where a key (any text, number etc.) is used to encrypt the data, and the same key is to decrypt the data Is used for The smallest change in the secret key will fail to decrypt the encrypted message. For example, encrypted text using AES encryption with Key Infosec will fail to decrypt another ciphertext, which was encrypted using the key INFOSEC. Asymmetric key cryptography is also called Public Cryptography (PKC), where two sets of keys are produced i.e. a public key and private key accordingly. A public key is used to encrypt the data, while a private key is used to decrypt that data. Similar to symmetric cryptography, the smallest change in any one of the two keys will make them useless to get the original data. The advantage of asymmetric cryptography is that you can share the public key with the whole world so that they can use it to send you encrypted data. And securely stored with the private key owner and it is used for decryption. One disadvantage of this type of cryptography is that if your personal key is lost or leaked, then you have to generate a new pair of the public and private key.

### Quantum Cryptography In Present

With the existing solution, we have a new problem due to the problem with every new solution. The matter is not different from this. Let’s see the problem first. The problem with symmetric cryptography is that the same key is used to encrypt and decrypt the messages. If for some reason the key leaks to a third party, then it can be used to decrypt communication between two trusted devices or individuals. In the worst case, communication can be blocked and changed. Today’s huge computing power (these days the Xbox and PlayStation also have large power in homes) can be used to crack the key used in symmetric cryptography. Another major problem with this kind of cryptography is to decide which key to use and how to share between reliable devices or individuals. Imagine a key should be shared between India and the United States, then that communication should be secured before sharing the key. Coming to the problem of asymmetric cryptography, it’s not something we are facing yet, but considering the speed of changing technology, we will face it soon. Most keys used in public-key cryptography are at least 128-bit keys that are considered very strong. An attacker can easily catch the public key because it is shared by the user.

### Quantum Cryptography Future

But to generate a private key for that public key, a large amount of calculation is included with permutations and combinations. Currently, a supercomputer is one that requires many years to crack you and complete PKC. But it will be very possible with the use of quantum computers that use quantum physics to operate and keep very high efficiency and calculation speed. Quantum computer is a theoretical concept and will use the atoms and molecules to computing at very fast speed. According to Moore’s law, the number of transistors doubles in every two years in an integrated circuit. This means that the speed of computing will increase to a very high level every two years. There are now 1.4 billion transistors in the Intel i7 processor integrated circuit. Obviously, the speed of computing will increase in the coming decades and the age of quantum computers will become a reality. Now it is very clear from our above discussion that the biggest problem with current cryptographic techniques is their protection in key and transmission.

## Discussion about this post