Double-Cut During the War of Resistance: My Wife Came from 1937

"Will it take several weeks to crack?"

Upon hearing this, the leaders were somewhat disappointed.

They even thought that with the help of later generations, they would be able to decipher the Japanese military's secret telegrams immediately!

But no one expected that, even with the help of later generations, it would still take so long to crack the most basic code.

"no way!"

Ma Hongwei shook his head and sighed: "The books and materials I brought only described the types of codes used by the Japanese army and their weaknesses, as well as commonly used military terms, but they did not contain a large number of Japanese military codes."

"The Japanese army's security teams, garrison units, military police detachments and other small internal short-distance communications occasionally used classical ciphers such as shift and simple Virginia ciphers. These types of ciphers are relatively easy to crack and can be deciphered in a short time."

"However, the main field forces of the Japanese army had long since abandoned those codes and were using random number book codes."

"This book contains random number ciphers. The random number changes to a new page every day. There is no fixed key string that can be brute-forced. This kind of cipher can artificially smooth out the characteristics of the code group frequency. Frequency statistics and overlap index solutions are basically ineffective."

"Although we have mastered the entire construction principle of the cipher, we still need a large number of identical ciphertext samples to deduce it, unless we have a codebook."

At this point, Ma Hongwei looked at the leaders and asked, "Gentlemen, have any of you captured any codebooks?"

"Alas, we never obtained the complete codebook!"

Political Commissar Luo sighed, "The Japanese army has strict regulations. When radio operators are facing capture or annihilation, they must immediately destroy their codebooks and coded telegram drafts. Codebooks have a higher priority than radio equipment."

"Even if we were able to capture the radio, we couldn't get the codebook; what we got were torn-up and burned fragments."

"yes!"

Deputy Division Commander Xu nodded and said, "The Japanese troops we are currently encountering are extremely resistant. Even if they are captured by us, they will commit suicide directly."

"So far, our entire Eighth Route Army has only captured one Japanese soldier prisoner. Even ordinary Japanese soldiers are like this, let alone those key personnel. Even if they don't want to die, they will be killed by other Japanese soldiers."

"I see!"

Ma Hongwei couldn't help but frown.

To crack the code, it would be necessary to continuously collect a large number of telegrams from the same radio station.

However, he has four computers here, and if the tasks are clearly divided, it can speed things up.

One unit is dedicated to cleaning and frequency statistics of ciphertext, a second unit is dedicated to searching for duplicate code groups and long duplicate segments, and a third unit uses a locally deployed large model to guess the semantic candidate of military sentences.

Ma Hongwei thought to himself, "If it's encrypted, I could buy some power supply units, pure training equipment, and shortwave receivers."

When he was searching for radio stations, he found that those transceivers had to be registered and could not be purchased in large quantities.

However, receivers that only receive and do not transmit can be purchased freely without even requiring a license.

While this receiver, which only has receiving capabilities, cannot be used to send telegrams, it is perfect for intercepting secret telegrams from the Japanese army.

In addition, you can buy an audio decoder, connect the receiver's output directly to your computer's sound card, and run CW decoding software on your computer to automatically recognize Morse code and convert it into text.

Of course, this intercepted Morse code is just ciphertext and cannot be directly decrypted, but it can save people the physical labor of manually copying the code.

Ma Hongwei looked at the group of leaders and said, "Commanders, my idea is to first teach a few people in the 129th Division how to use computers, and then send them to the Eighth Route Army headquarters to specifically work on cracking Japanese codes."

"No!"

Deputy Commander Peng said, "I think it's best to settle you in the 129th Division. After all, it's the closest place for you all to come here!"

"If you encounter any problems at the Eighth Route Army headquarters, we'll have to send you there again, which will take up a lot of time."

The other leaders also thought it made a lot of sense.

Commander Liu said, "If that's the case, then I'll arrange for people to start learning from Comrade Hongwei. He'll be going back in two days, so we must make sure they learn how to use a computer in these two days."

Ma Hongwei asked Division Commander Liu, "Sir, I wonder if your 129th Division has intercepted any coded messages from Japanese radio stations?"

"Logically speaking, this should be the responsibility of the Second Bureau of the Central Military Commission; our frontline troops are not involved."

Commander Liu nodded and said, "But ever since the Central Committee asked us to actively cooperate with your work last time, I have arranged for the communications section to allocate manpower and radios to intercept radio messages from the nearby Japanese army. We have managed to accumulate some secret messages from the garrison troops in the county town."

"Oh?"

Ma Hongwei immediately became interested.

He said to Commander Liu, "Sir, could you please have someone bring these coded messages over? Let's try to decipher them now!"

"good!"

Commander Liu nodded and said, "I'll go and get someone right away."

After saying that, he turned and left the house.

Before long, Commander Liu led several Eighth Route Army soldiers into the house.

These all belong to the Confidential Affairs Section and the Communications Section.

They were also holding a lot of papers in their hands.

"Greetings, sir!"

Upon entering the room, several Eighth Route Army soldiers immediately began to salute.

Their gazes fell on Ma Hongwei and Xia Weiwei, filled with a hint of curiosity.

After all, the room was full of Eighth Route Army commanders, and these two young men were actually here.

Commander Liu introduced to Ma Hongwei: "This is Section Chief Yang of the Confidential Section of my 129th Division, and this is Section Chief Zhao of the Communications Section. The others are personnel from the Confidential Section and the Communications Section."

Then he said to the Eighth Route Army soldiers, "Your next task is to cooperate with Comrade Hongwei to decipher the Japanese army's coded messages and learn how to use computers. This is related to the future of our Eighth Route Army. If anyone doesn't study hard, none of us will be happy."

"Yes, sir!"

Although everyone agreed, their gazes toward Ma Hongwei were filled with suspicion.

The other party doesn't look very old, how could they be more useful than them?

However, they wouldn't reveal it directly in front of so many leaders.

But judging from their expressions, they were clearly not convinced.

"Hello, comrades!"

Ma Hongwei looked at the group and said with a smile, "Over the next few days, I will be teaching you how to use computers and how to decipher the most basic three-digit short codes and single-label substitution codes used by Japanese platoons and battalions!"

Then he asked, "Gentlemen, could you hand over the Japanese coded messages you've collected these past few days?"