Caesar's Cipher vs Al-Kindi

One of the successes of secret messages that can then be known to others, hundreds of years later when unlocked!

Julius Caesar had used a substitution cipher around 58 BC which is now known as the Caesar Cipher. He used this cipher with a pattern of shifting each original letter to another letter. He ordered this cipher so that the message would be unknown to the enemy, only patterns known and approved by him and his troops could be sent. The process of this message was description-encryption-description. The greatness of this cipher was recognised by its use by world military leaders for hundreds of years. 

JULIUS CAESAR 1: "I have fought and won. But I have not conquered the human spirit, which never gives up."

However, Caesar's cipher was broken by the Arab scientist Al-Kindi 800 years after its invention. Al-Kindi held the key to the cipher, which was the frequency of each letter.