Several of the eap protocols use which creates a ciphertext from cleartext.

In a cellular network each cell is controlled by a tower what are these towers called?

What engine component is shown in the above figure?

Write a program that asks the user to enter the name of an input file. if the file does not exist, the program should prompt the user to enter the file name again. if the user types quit in any uppercase/lowercase combinations, then the program should exit without any further output.