The Rise of the Empire

Therefore, this time the Prussians learned to be smart. No matter how many times this simple correspondence is done, the problem cannot be completely solved, because they can always trace the source and find a one-to-one correspondence to determine the password. So, they came up with the adfgv frame password. The frame of this password is a 5*5 letter matrix, used to correspond to 26 English letters, what? You said there are only 25? Then this is easy, just let i and j correspond to the same letter. \u003c/p\u003eThe reason why it is called adfgv password is that one of the very important reasons is that the horizontal and vertical coordinates of the 5*5 frame are represented by these 5 letters. According to the letters in the plaintext, and then replace them with the horizontal and vertical coordinates of the frame, this becomes the first step of encryption. In fact, this encryption method is easy to crack. This is the simplest classical encryption method, but it is a pity. Yes, this time the Germans added the key again! The so-called key is another shift code. When using the key to shift, use the key character to add an extra column to the original coordinate system, and then write the ciphertext encrypted for the first time in the order of 5 lines. Go in, and then transcribe according to another alphabetical key, thus forming the final ciphertext. \u003c/p\u003eThe key to the difficulty of deciphering this kind of password is that the key and the shift password are changing every day. Even if you find out, it will be useless, or the initial corresponding table of 5*5 is meaningless if you get it Big, the other party can just write a 5*5 form at will, it is possible to crack it, but if you use guessing, or simply find a one-to-one correspondence method, it is difficult to guarantee timeliness and accuracy . What would we do in an era without computers? \u003c/p\u003eThere is only one way, and that is to look for telegrams with the same beginning, because this shows that they use the same split key and shift key, and then filter through mathematical methods. Of course, an objective condition is also needed here, that is, there is a large enough amount of information that appears repeatedly, and there is enough material to decipher it. This is why the Bavarian intelligence team failed to decipher the other party at the beginning. In the process of accumulating materials! \u003c/p\u003e From the sixth week, the whole thing began to turn around. On the 38th day after the game started, the prince handed over the first deciphered telegram to the Kaiser. Two days later came the second letter. Then before the week was over, 6 telegrams were sent to Berlin! This meant that exactly 120,000 marks had been transferred from the Kaiser's account to the prince's name. And when the seventh week came, in just one week, a full 18 telegrams were deciphered! In less than two weeks, the Kaiser lost 500,000 marks! \u003c/p\u003e"Who can tell me what's going on? Didn't I ask you to change the comparison table and the key? Why is the other party's deciphering speed still so fast? We sent the telegram in the morning, and when I was drinking in the afternoon During tea time, Bavaria will send plaintext! I feel that our IQ has been insulted, and the other party looks at us like a fool! This is our shame! The empire spends a lot of money for you and Those so-called cryptography experts under you have provided the best conditions, and look at what you have done?" The Kaiser said angrily. \u003c/p\u003e "Now, it's the seventh week, and you can't even decipher a single telegram, but what about Bavaria? They have deciphered 24 telegrams from us! No matter how we change the frame and key If you can’t change this result, then I can only say that your method is a failure, and the encryption method you proposed is not trustworthy at all!” At this point, even the Kaiser, who had no research on cryptography, knew that he Lost, because the other party has adapted to this encryption method, and the room for expansion of this password is too small, so no matter how much you change it, you can't fail. \u003c/p\u003e"Theoretically, the corresponding table of 5*5 will have enough variations,

We can increase the difficulty of deciphering by randomly changing the corresponding method, but the intelligence needs to be transmitted stably, and the corresponding table itself cannot be changed at will. A piece of our information may eventually be transmitted from the General Staff to a division commander. It would be a very tedious process to change the corresponding table. "\u003c/p\u003e" Also because of the comparison relationship of 5*5, our shift password can only be 5 digits, the other party can find the breakthrough through enumeration and statistics, and if it corresponds to the facts, as long as they can find The key to one of the letters, then other information using the same key will have no secrecy at all. We admit the other party's ability in deciphering, but I must say that the Kingdom of Bavaria is more talented in encryption , They have come up with a brand new encryption method, this method is simply unbreakable in our opinion! Because every phrase is different in every telegram! "Schlieffen was convinced that he lost, he did not justify his failure, but admitted it clearly!\u003c/p\u003e "That is to say, we lost again? An unbelievable expression appeared on the Kaiser's face, "But just now you have said that the ciphertext of each phrase is different, which means that you have already determined some phrases, is that so?" "\u003c/p\u003e"Yes, the Bavarians are very confident in their cipher system. They will even take the initiative to provide us with the correct answer after 3 days, and then we will deduce the ciphertext according to the given plaintext. But it is a pity that the correspondence order of letters in each of their ciphertext telegrams is chaotic, at least we cannot see the rules, and when we use the same key, the correspondence of the files is certain, even if we change the key every day Spoon, still can't produce their effect. "Schlieffen was convinced that he lost this time.\u003c/p\u003e" Well, well, well, we failed again! Take a look at who our general staff is made up of! I'll give you one more week at the end. I hope you can at least see something. "Although the Kaiser knew that Schlieffen was helpless after saying these words, he still didn't want to give up.\u003c/p\u003e"I will try my best. "Schlieffen said in a deep voice.\u003c/p\u003e"Your Highness, if there is no accident, His Majesty William will soon be overwhelmed, right? "At the same time, in Schwannburg, Earl Schelling said to **** with the telegram that was just deciphered today.\u003c/p\u003e But the final result did not exceed the surprise of the Prussians. The relationship is so messed up that nothing can be done about a cipher that cannot be deciphered by any existing mathematical method.\u003c/p\u003e "Go to Bavaria and get the encryption method of the new cipher! I want to know where we lost! "The Kaiser ordered.\u003c/p\u003eThe third update is here~~~! Please subscribe\u003c/a\u003e~~~!\u003c/p\u003e\u003c/div\u003e