Q11Information Security Systems
Question
4 marks
Explain the operational steps of the RSA algorithm with a simple outline.
Answer
RSA algorithm relies on the mathematical difficulty of factoring large prime numbers.
The RSA algorithm involves three main steps: Key Generation, Encryption, and Decryption. In Key Generation, two large primes (p, q) are chosen to compute n = pq and the totient phi(n). A public exponent 'e' and a private exponent 'd' are calculated such that (ed) mod phi(n) = 1. The public key is (e, n) and the private key is (d, n). For Encryption, ciphertext C = P^e mod n. For Decryption, plaintext P = C^d mod n. RSA's security stems from the computational difficulty of factoring 'n' back into 'p' and 'q'.