Final answer:
The two numbers P and Q used in RSA encryption are prime numbers and often consist of thousands of bits to ensure encryption strength. While small primes can be used for learning or demonstration, actual RSA encryption requires large primes for security.
Step-by-step explanation:
The two numbers, P and Q, used to find the keys in RSA encryption can be small numbers as long as they are prime. RSA encryption involves two key components: the public key and the private key. These keys are generated from two large prime numbers, P and Q. The security of RSA encryption relies on the fact that factoring a large number, particularly the product of two prime numbers, is computationally difficult. Therefore, it is essential that P and Q are prime numbers. While they can be small for educational or demonstrational purposes, in practice, the numbers P and Q usually consist of thousands of bits to ensure a high level of security.