In this blog series , We will learn about encryption and decryption basics in a very casual fashion . We will start discussing from origin of cryptography and then learns about the modern techniques

One of the important and main tech in encryption is **Cryptography**

Cryptography is a tech which is very very common and which is used in everywhere right now weather any software as follows :

- Routers we use in our homes
- Whatsapp we use to send receive messages
- Any site we are opening on https
- ……. And so on ..

Now , At the same time cryptography is very common , it is extremely complex also . Complex in understanding , implementing and even using it correctly .

**Need of Cryptography: **

To answer this let’s answer the following

- Why we need password on our phone
- Why to lock the door of our home when going outside and take keys with ourselves

Same is answer to use cryptography – **To assures that the sender or receiver is the right one and they can only see the right form of data **

To understand how it works let’s start from old age method known as : **Caesar Cipher**

**Caesar Cipher**

The Caesar Cipher is a type of substitution cipher in which each letter in a plaintext is shifted a certain number of places down the alphabet. This simple encryption technique is named after Julius Caesar, who used it to encrypt messages sent to his officials. The process of encryption is simple, a shift value ( also known as key) is chosen and each letter of the plaintext is shifted by that number of positions down the alphabet.

For example, with a shift of 3, A would be replaced by D, B would be replaced by E, and so on.

Plaintext:Sahil

Shift(Key): 3

Ciphertext:Vdklo

To decrypt the message, the shift value is used in the opposite direction.

Ciphertext:Vdklo

Shift(Key): -3

Plaintext: Sahil

It is important to note that the Caesar Cipher is very easy to break and should not be used for any serious encryption purposes as it can be broken by simple methods such as frequency analysis.

Here Algorithm is Simple: shift a letter N number of times and then replace it with that letter and Continue this process till our plain text will be Converted into cipher text .

A Caesar Cipher table is a tool that can be used to manually encrypt and decrypt messages using the Caesar Cipher method. It is a table that lists all of the letters of the alphabet and their corresponding encrypted or decrypted letters, based on a chosen shift value (or key).

Here is an example of a Caesar Cipher table with a shift(Key) value of 3:

Plaintext | Ciphertext |

A | D |

B | E |

C | F |

And so on …

With Caesar cipher, someone can easily reverse engineer this Caesar cipher text and decode the messages encrypted using this algorithm by identifying the pattern , one can easily determine the key . This was just an example to get the readers familiar with the cryptography and encryption decryption concepts .

Till Now we have heard about some important terms

**Cryptography****Algorithm****Plain Text****Key****Cipher Text**

Please keep them in mind as these are the generic terms used everywhere in world of encryption and decryption .

In next Blog we will gossip about some other things like

- Making strong Algo as compare to caesar cipher
- What is latest Algo used now a days
- What type of Cryptography Techniques are present and when one should be used
- and so on …

Stay tuned for next part …

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