Security in Computing 5th Edition by Shari Lawrence Pfleeger, Charles P Pfleeger, Jonathan Margulies

Exercise 15

A 32-bit IP addressing scheme affords approximately 4 billion addresses. Compare this number to the world’s population. Every additional bit doubles the number of potential addresses. Although 32 bits is becoming too small, 128 bits seems excessive, even allowing for significant growth. But not all bits have to be dedicated to specifying an address. Cite a security use for a few bits in an address.

Step 1 of 2

32-bit IP Address

The world population is close to 7 billion as reported by the United States Census Bureau (USCB). Each individual who uses internet addresses has a minimum requirement of 3 (home computer, work computer, and mobile computer). So even if only 50% of the population (low estimate) has access to computers, still the numbers of IP addresses required is close to 10 billion. Compared to this requirement, the number of addresses generated using a 32-bit scheme is 4 billion, which does not cover even half the requirements.