Imagine two people who share an important secret have to split up. This requires them to communicate private information from a distance. However, an ease dropper named James also wants this information and has the ability to intercept the message. So these two people, Alice and Bob decide to communicate using letters written in some kind of secret code. The following analogy is helpful.
First, Alice locks her message in a box, using the lock that only her and Bob know the combination to. This is known as ‘encryption’. Then the locked message is sent to bob. When bob receives the box, he opens the box using the code they shared in advance. This is called decryption. Cryptography begins when we abandon physical locks and use ‘ciphers’ instead. Think of them as virtual locks. Ciphers allow them to scramble and unscramble the messages so that they would appear meaningless if James intercepted the message. Cryptography has been around for thousands of years. It has decided wars and is at the heart of the world wide communication network today.
This is basically how I understood the basic concept of cryptography.
The Wonderful World of Algorithms 
It is great how you come up with your own example/method in order to understand cryptography. Hopefully, this will provide a better understanding of cryptography for others as well. The reference of cryptography as an “virtual lock” is an extremely interesting idea and something I haven’t thought about. Thank you so much for an informative post! 🙂
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