1. Chinese Reminder Theorem [Marks 25%]. Write a Python program called crt.pythat finds the value of x that satisfies a system of congruencies of the form:x ≡ a (mod r)x ≡ b (mod s)x ≡ c (mod t)where...

1. Chinese Reminder Theorem [Marks 25%]. Write a Python program called crt.pythat finds the value of x that satisfies a system of congruencies of the form:x ≡ a (mod r)x ≡ b (mod s)x ≡ c (mod t)where a, b, and c are integers; and r, s, and t are pairwise relatively prime positiveintegers (i.e., gcd(r, s) = gcd(s, t) = gcd(r, t) = 1). Your programprompts the user for the values of a, b, c, r, s, and t, and outputs the value ofx that satisfies the system of congruencies. Hint: see the NumPy Ntheory classreference: http://docs.sympy.org/dev/modules/ntheory.html. Submit your Pythonsource code crt.py.2. Symmetric Encryption in Python [Marks: 25%]. Use the “cryptography” library ina Python program called symmetric.py that prompts a user for a message to encryptusing either AES or 3DES encryption. The program prompts the user for the plaintextand it automatically generates the necessary key and shows the correspondingciphertext on the screen along with its decryption back to the original plaintext. Hint:You may use the example code from:https://cryptography.io/en/latest/hazmat/primitives/symmetric‐encryption/. Submityour Python source code symmetric.py.