my teacher asked the class to do a digial circuit that encrypted a message using cesar's cipher, and a circuit to decrypt, but my only idea is to solve it using a circuit that does P + K mod N, where P is The position of the letter in the alphabet, K the value of the key, and N is the number of letters in the alphabet. Or use an adder circuit, for example, when P and K have 4 bits, and N equals 8. Even if an overflow occurs, the sum between them would still give me a result within my representation. However, in my case I am using an alphabet with 94 symbols, so how can I solve this problem?
I appreciate any help.