Given the letter-number cipher: a=00, b=01, c=02, etc., encrypt the word 'hi' and decrypt its ciphertext using RSA. The public key is (5,35) and the private key is (29,35).
I know that 'hi' is represented numerically as 0708, and encrypting it using (0708^5)mod35 gives 8 as the answer. My instructor then said that I have to pad the result with 3 leading zeroes to get a four digit value (0008) which represents the ciphertext 'ai'.
I find it hard to decrypt it, as (0008^29)mod35 gives 8 as the answer, and I don't see how I can manipulate this result to get a value that gives me the original plaintext.
Can you please point out where I went wrong or what I'm failing to understand?