The Encryption Process

• The process of encrypting a binary message is very simple.
• The binary message is simply xor'ed with another binary sequence.
• The second sequence should be random.
• Example: Let the message be ``ECE 101.''
• Using ASCII encoding, we get:
  45x 43x 45x 20x 31x 30x 31x
• In binary form:
  01000101 01000011 01000101 00100000 00110001 00110000 00110001
• Now select a random sequence of equal length, e.g.,
  1010011 1000011 0101101 1101110 0110010 1010001 1101010
• The encrypted message is then:
  

  E	C	E	SPACE	1	0	1
  45x	43x	45x	20x	31x	30x	31x
  1000101	1000011	1000101	0100000	0110001	0110000	0110001
  			$\oplus$
  1010011	1000011	0101101	1101110	0110010	1010001	1101010
  			=
  0010110	0000000	1101000	1001110	0000011	1100001	1011011
  16x	00x	68x	4Ex	03x	61x	5Bx
  SYN	NULL	h	N	ETX	a	[

• The encrypted message can now be transmitted and is meaningless to anyone intercepting it.