The RSA (Rivest–Shamir–Adleman) algorithm is a widely used asymmetric cryptographic method in computer networks for secure data transmission, authentication, and key exchange. It operates with a public key for encryption and a private key for decryption, relying on the computational difficulty of factoring large semiprime numbers.

Core Steps of RSA:

• Key Generation Select two large primes p and q. Compute modulus n = p × q. Calculate Euler’s totient: φ(n) = (p − 1) × (q − 1). Choose public exponent e such that 1 < e < φ(n) and gcd(e, φ(n)) = 1. Compute private exponent d as the modular inverse of e mod φ(n). Public key: (n, e), Private key: (n, d).

• Encryption Convert message M to an integer < n. Compute ciphertext: C = M^e mod n

• Decryption Recover message: M = C^d mod n

Python Example: