I am working on decrypting ciphertext in monoalphabetic substitution algorithm. I tried to decrypt using frequency histogram of English alphabets individually. The percentage of these frequencies can be found here, but the plaintext I got from this was not informative. So I tried searching online and found this website for decrypting monoalphabetic substitution. The result was amazing in this site and they used digrams for decryption. So I tried using digrams but the results I got was not good.
Can someone guide me through this decryption?