Suggestions about how to find decryption formula with some already known encrypted values : <p>Can you please suggest a strategy to use to decrypt some encrypted values.</p>

<p>I have some strings encrypted, let's call them: A,B,C,D
and I already know the decrypted values of some of them, let's say, I know :</p>

<p>A->A'</p>

<p>B->B'</p>

<p>Is there some trick to use, to find the encryption formula? in order to decrypt the missing ones (C and D)?</p>

<p>Any help would be appreciated.</p>
