Design a Hash Function - Discrete Mathematics No Programming Required -- 3

A hash function is a way of taking a character string of any length, and creating an
output of fixed length. This creates a 'fingerprint' of the character string. Hash
functions usually use modular arithmetic to create a fixed length output.
Your task is to design a hash function!
Choose two character strings that are between 5 and 15 characters long (including
spaces). For example. "Julia 123" or "Password!".
(a) (i) Design a function h whose input is a character string of any length and
whose output is a (base 10) whole number. Your function must make
non-trivial use of the ASCII values of each character. (For example,
add all the ASCII values together – but don’t use this example!)
(ii) Explain how your answer to (a)(i) satisfies the definition of a function.
(b) Calculate the outputs of your function h for the two character strings you
defined.
(c) Choose a modulus m of between 4 and 12.
Calculate the least residues modulo m of each of your two answers to (b),
showing full working.
(d) Give two reasons why it might be useful to create hash functions like these as
a way of storing passwords in a database