In cryptography, Encryption is the process of encoding information. This process transforms the original representation of the information information known as "plaintext" into another form called "ciphertext". The goal is that only the parties decrypt the encrypted message in order to retrieve the original message. There are several encryption algorithms but in this assignment, our goal is quite modest because we just want to implement one of the first encryption algorithms known as 'Caesar cipher https://en.wikipedia.org/wiki/Caesar_cipher This encryption algorithm just shifts the characters according to a predefined constant and we assume that the text to encrypt contains only the lower case letters of the Latin alphabet, i.e. the 26 letters from "a" to "z", inclusive. Here are the specifications of our implementation: - The EncryptionCesar class will contain just the one variable needed for encryption which is the offset. It will contain just 3 methods: the constructor and the two functions Encrypt and Decrypt. - The main method is also defined in the EncryptionCesar class. It will just be used to execute a simple visual test which is to encrypt and decrypt a string sent to the command line. You are asked to : - Complete the EncryptionCesar class - Create the UnitTestEncryptionCesar class. This class will contain a single test unit which must have the signature @Test public void testEncryption(). The content of the code must generate random strings of characters 10 times, encrypt them then decrypt them and verify that the decrypted text matches the original text. o Hint: You can use the Random class to generate random strings. As an example, here is the result of the execution of " java EncryptionCesar lecoursnestpenn ennuyant 3"

Message avant Encryption: lecoursnestpasennuyant Message apres Encryption: ohfrxuvqhvwsdvhqqxbdqw (decalage=3) Message apres Decryption: lecoursnestpasennuyant