Cyber Forensics: From Data to Digital Evidence

CHAPTER TWO

Binary to Decimal

IN CHAPTER 1 WE INTRODUCED the basic concepts of numbering systems and how data is moved and manipulated. The life cycle of data, from its humble beginnings as electronic bits and bytes, evolving into characters, then words, finally emerging as a language, then as information and eventually into potential evidence. Understanding how evidence emerges from data, is pivotal in successful forensic investigations.

We continue now in the next step of our cyber forensic learning process, moving from our humble binary beginnings of our two-state world, growing now beyond binary to decimal and back again, gaining a deeper understanding of the math behind the forensics and how a knowledge of the math is essential in understanding even the most basic cyber forensic investigation.

So, as we probe deeper into an understanding of what happens behind the flash and sizzle of forensics, let’s begin where we left off.

AMERICAN STANDARD CODE FOR INFORMATION INTERCHANGE

The history of ASCII and its development were discussed at length previously, and we now know that the characters identified by 2 ^ 7 or 128-bit unique characters are known as American Standard Code for Information Interchange/extended ASCII or just ASCII.

ASCII characters are assigned a decimal value because binary cannot be directly converted to ASCII, and silicon-based computing devices can only compute in binary math. However, binary can be converted into a decimal value, and this decimal value is ...