Q4 Bob believes that he has come up with a nifty hash function. He assigns a numeric value V_Charto each letter in the alphabet equal to the letters position in the alphabet, i.e., V_A= 1, V_B= 2, , V_Z= 26. For a message, he calculates the hash value H = (V_{Char 1} x V_{Char 2} x V_{Char 3} x V_{Char N}) mod(26).

Bob uses this function to send a one-word message, GLARE, to his banker 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 Bobs original hash value.

Give definition and properties of the hash function.

Show a message that Alice may have used to spoof Bobs message, and demonstrate that its hash value collides with Bobs original hash.