Final answer:
The question involves the creation of a public key for encryption using prime numbers in mathematics, specifically within cryptography. A pair of primes is chosen, and their product along with another number relatively prime to (p-1)(q-1) forms the public key (n, e), used for encrypting messages.
Step-by-step explanation:
The question describes the initial steps of setting up a public key encryption system, which is a concept in cryptography within the field of mathematics and computer science. The process involves choosing two prime numbers, p and q, then computing their product n=pq to form part of the public key.
The other part of the public key is an integer e, chosen such that it is relatively prime to (p-1)(q-1), which means e and (p-1)(q-1) share no divisors other than 1. The public key consisting of (n, e) can then be used to encrypt messages.
For example, if we select p = 5 and q = 11, then n = 55, and (p - 1)(q - 1) = 40. We could choose e = 3 because 3 is relatively prime to 40. Hence, our public key is (55, 3). This key can be used to encrypt data using a specific encryption algorithm, typically the RSA algorithm in this kind of cryptographic system.