History of Cryptography.....

                                    

⭐ Cryptography, the use of codes and ciphers to protect secrets, began thousands of years ago. Until        recent decades, it has been the story of what might be called classic cryptography — that is, of            methods of encryption that use pen and paper, or perhaps simple mechanical aids.

 Over the centuries, various cipher methods, physical devices, and aids have been used to encrypt and decrypt text: 

• Scytale

     Earliest cryptography method was used by the Spartans in ancient Greece

                          

 • Caesar cipher 

Julius caesar use to use to encrypted message to communicate with his generals. He Use shift by 3 times in every letter. If he wants to write letter "A" → he relapsed A with D.

                      

 • Vigenère Cipher 

In 1586, Frenchman Blaise de Vigenère described a polyalphabetic system of encryption. It became known as the Vigenère Cipher. 

 Based on the Caesar cipher, it encrypted plaintext using a multiletter key. It is also referred to as an autokey cipher. 

                     

 • Jefferson’s encryption device 

  Thomas Jefferson, the third president of the United States, invented an encryption system that was believed to have been used when he served as secretary of state from 1790 to 1793. 

 

                 

 • German Enigma machine 

Arthur Scherbius invented the Enigma in 1918 and sold it to Germany. It served as a template for the machines that all the major participants in World War II used.  

 It was estimated that if 1,000 cryptanalysts tested four keys per minute, all day, everyday, it would take 1.8 billion years to try them all. 