Bob believes that he has come up with a nifty hash function.

Bob believes that he has come up with a nifty hash function. He assigns a numeric value VCharABZChar 1 Char 2
to each letter in the alphabet equal to the letter’s position in the alphabet, i.e., V = 1, V = 2, …, V = 26. For a message, he calculates the hash value H = (Vx Vx VChar 3 …x VChar N) mod (26).

Bob uses this function to send a one-word message, “PLANET” to his supervisor Bill, along with his calculated hash value for the message. Alice is able to intercept the message and generates an alternative message that has a hash value that collides with Bob’s original hash value.

Give definition and properties of the hash function.

Show a message that Alice may have used to spoof Bob’s message and demonstrate that its hash value collides with Bob’s original hash.