Scientific Foundation
What is number theory & modern cryptography?
Number theory studies the algebraic properties of integers (ℤ). By the Fundamental Theorem of Arithmetic, every integer n > 1 has a unique prime factorization. The Euclidean Algorithm computes gcd(a, b) in logarithmic time, with Bézout's Identity guaranteeing integers x, y such that ax + by = gcd(a, b). Modern RSA cryptography exploits the computational asymmetry between prime multiplication (easy) and prime factorization of large semiprimes n = p·q (intractable), relying on Euler's Totient Theorem: a^φ(n) ≡ 1 (mod n).
