For a college course -- CNIT 140: "Cryptography for Computer Networks" at City College San Francisco Instructor: Sam Bowne More info: https://samsclass.info/141/141_F17.shtml

1. XOR
Bits and Nybbles

2. One Bit
0 ⊕ 0 = 0
0 ⊕ 1 = 1
1 ⊕ 0 = 1
1 ⊕ 1 = 0
In book, XOR is ⊕
In Python, XOR is ^

3. One Bit in Python

4. Two Bits
00 ⊕ 00 = 00
00 ⊕ 01 = 01
01 ⊕ 01 = 00
01 ⊕ 11 = 10

5. Two Bits in Python

6. Four Bits
0000 ⊕ 1000 = 1000
1100 ⊕ 0001 = 1101
1111 ⊕ 1110 = 0001
0101 ⊕ 1010 = 1111

7. Four Bits in Python