In RSA, given p $107,$ q $113,$ e $13,$ and d $3653,$ encrypt the message

$$THIS IS TOUGH$$ using $00$ to $26($A: $00$ and space: $26)$ as the encoding

scheme. Decrypt the ciphertext to find the original message.

Assume we have a very simple message digest. Our unrealistic message

digest is just one number between $0$ and $25.$ The digest is initially set to $0.$ The

cryptographic hash function adds the current value of the digest to the value

of the current character $($between $0$ and $25).$ Addition is in modulo $26.$ What is

the value of the digest if the message is $$HELLO$?$ Why is this digest not

secure$?$