Cipher and Keys

A Cipher can also be called as an Algorithm about how to perform encryption and Decryption.

There are multiple methods how it can be done few of them are

Substitution – This uses different letter for a particular letter. meaning.

 'A' could be 'X'

(A is Cipherd to be X)

Poly alphabetic – This uses multiple letter for a particular letter (alphabet) Like for Example 

‘A’ – ‘DCE’
(A is cipher and is DCE)

Transposition – This rearranges the letters in different form

Example - “This is Secret”

T S S R

H I E E

I S C T

(It's just jumbling of words)

What’s keys then?

Keys are somethings that are used to decry-pt these cipher Encryption.Which has be to know to both the Receiver and the Provider of the packet.

A one-time pad (OTP) is a good example of a key that is only used once.
if we want to encrypt a 32-bit message, we use a 32-bit key, also called the pad, which is
used one time only. The key in this case is the one-time use pad. The pad must also be known by the receiver if he wants to
decrypt the message.