Binary Exponentiation and Modular Arithmetic
Efficient computation of $a^b \bmod m$ utilizes the binary representation of the exponent $b$. By expressing $b$ as $\sum_{i=0}^{k} c_i \cdot 2^i$ where $c_i \in {0,1}$, the power decomposes into a product of squared terms: $a^b = \prod_{i=0}^{k} (a^{2^i})^{c_i}$. The algorithm iterates through each...