Alice and Bob shared a secret key using the following story.
Williams is a handsome boy. He is calm and brilliant. He lost his parents in an accident when they went on an uphill drive. One day, he went swimming with his five friends in a nearby river. It was autumn. His friends had gone deeper into the river but he stayed at the bank. Suddenly he heard the voices of his friends, shouting for help. He saw a large crocodile attacking them. He took a knife from his bag and jumped into the river to save them. He started fighting with the crocodile. He was wounded in the leg and wrist. The crocodile was also wounded severely by him. After a long fight, the crocodile left him and his friends brought him to the bank. All of his friends hoped that he would recover soon. Later he was rewarded for his courage by the government. The award was presented by a colonel of the US army. The colonel signed a cheque of $200 and handed it over to Williams.
Alice send to Bob another message "Keep calm to decipher it".
An intruder intercepted the message and tried to decipher it, but failed. Perhaps he is not calm. Can you decipher it?
Keep silent while reading the story.
Remove unwanted things.