Which of the following uses both a public and private key?

A. RSA B. AES C. MD5 D. SHA

Answer: A

Explanation: The RSA algorithm is an early public-key encryption system that uses large integers as the basis for the process. RSA uses both a public key and a secret. RSA key generation process:

1.

Generate two large random primes, p and q, of approximately equal size such that their product, n = pq, is of the required bit length (such as 2048 bits, 4096 bits, and so forth). Let n = pq Let m = (p-1)(q-1)

2.

Choose a small number e, co-prime to m (note: Two numbers are co-prime if they have no common factors).

3.

Find d, such that de % m = 1

4.

Publish e and n as the public key. Keep d and n as the secret key.