1. Which of the following refers to coding and decoding of information as a mean of data protection against unauthorized access where the same key is used? a. conventional encryption b. data diddling c. DES 2. Which of the following is one of the most widely used encryption schemes developed in 1977 by the National Bureau of Standards? a. DES b. conventional encryption c. data diddling 3. Which of the following refers to a method in which encryption and decryption are performed using two different keys, one public and one private? a. public key encryption b. private key encryption c. DES 4. Which of the following refers to a cipher in which plaintext and ciphertext are integers between 0 and n-1 for some n? a. triple DES b. DES c. RSA Algorithm 5. Which of the following refers to an authentication mechanism that enables the creator of a message to attach a code that guarantees the source and integrity of the message? a. digital signature b. public key c. public key certificate