There is an issue with increasing the mod value: if the mod value is connected with the number of characters, moving to mod 29 means that our plaintext and ciphertext would need 29 characters. Since the English alphabet only has 26 characters, three additional characters would need to be added to the character set... maybe something like A,B,C,D,E,F,G,H,1,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,@,#,$ Question #2: The mod 37 is a good choice because it is prime, but it requires including an additional 11 characters. What 11 characters would you add to the traditional English alphabet? Explain why you think including those 11 characters would be useful for writing plaintext. Having to find additional characters for increasing the mod values might get messy. Just think of how many characters would need to added for the mod value of 517! The ciphertext created by modern electronic cipher systems use only numbers -- for example, the plaintext "HELLO" converted into ciphertext using key 3 in a multiplicative substitution cipher mod 26 would appear as "24 15 36 36 45" -- which means the mod value can be increased without having to worry about adding additional characters. In fact, most ciphers in use today use mod values generated by multiplying two very large (100+ digit) prime numbers. There is an issue with increasing the mod value: if the mod value is connected with the number of characters, moving to mod 29 means that our plaintext and ciphertext would need 29 characters. Since the English alphabet only has 26 characters, three additional characters would need to be added to the character set... maybe something like A,B,C,D,E,F,G,H,1,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,@,#,$ Question #2: The mod 37 is a good choice because it is prime, but it requires including an additional 11 characters. What 11 characters would you add to the traditional English alphabet? Explain why you think including those 11 characters would be useful for writing plaintext. Having to find additional characters for increasing the mod values might get messy. Just think of how many characters would need to added for the mod value of 517! The ciphertext created by modern electronic cipher systems use only numbers -- for example, the plaintext "HELLO" converted into ciphertext using key 3 in a multiplicative substitution cipher mod 26 would appear as "24 15 36 36 45" -- which means the mod value can be increased without having to worry about adding additional characters. In fact, most ciphers in use today use mod values generated by multiplying two very large (100+ digit) prime numbers