Write 400–600 words that respond to the following questions: What are cryptography and cryptanalysis? What is earlier reason for the use of cryptography? Fermat’s theorem and Euler’s theorem are the two theorems that play important roles in public-key cryptography. Explain each theorem in details their roles in public-key cryptography. Explain the Chinese Remainder Theorem that have been discovered by the Chinese mathematician Agrawal in 100 A.D.Respond to at least 2 of your fellow classmates with at least a 100-word reply.Please note: Be in APA format including your references. Be 400–600 words long (not including title and references). Do not re-state the questions. Include two sources (i.e. two references).