Modular Arithmetic in Cryptography: The Engine of Digital Security
Welcome back to izytech.dev ! In the previous article , we looked at why mathematical precision matters and how prime numbers and the Greatest Common Divisor are the building blocks of computer security. Today we take an important step forward and introduce the most important working tool of this field: Modular Arithmetic . If the concepts from the first lesson were the building materials, modular arithmetic is the real engine that powers modern cryptographic algorithms. Let's see how it works and why we use it every day, often without even noticing. What Is Modular Arithmetic? (The Math of the Clock) In simple terms, modular arithmetic is the math of remainders . Instead of moving along an infinite number line, we work inside a limited, cyclical system, focusing only on what is left over after a normal division by a specific number, called the modulus . A practical example we all use is reading a clock. Let's say it's 14:30 and you need to leave...