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

A.
RSA

B.
AES

C.
MD5

D.
SHA

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 = pqLet 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.