On Windows systems, the main executable file has a(n) ________ extension.

A subprocedure is also called a(n) ____________________.

Fill in the blank(s) with the appropriate word(s).

A __________ cipher processes the input one block of elements at a time, producing an output block for each input block, whereas a stream cipher processes the input elements continuously, producing output one element at a time.

Fill in the blank(s) with the appropriate word(s).