Chapter 241 Just one day!
As for why we didn’t just use the confidential channel, the reason is the same as before: the confidential channel was too good and not suitable.

However, there are indeed two confidential telephone lines used to ensure dispatch coordination. Once they are connected, they will not be disconnected. In this era, one can really say: heroic!

With the exchange of instructions and close cooperation between the two sides, the two experimental communication lines were connected. After that, all the telephone bureaus along the two lines were working to ensure the smooth operation of the lines. In the words of the leader of the Postal and Communications Commission, unless the reactionaries counterattacked, the two lines could not be disconnected.

Can the reactionaries counterattack? Obviously not.

The experiment went smoothly. After all, both sides were elites from their respective units, as were the line support personnel from the telephone bureaus along the way.

Basically, there were no problems and Gao Zhendong did not need to intervene too much. The entire experiment went smoothly.

The two leaders of the Defense Work Committee and the Postal Communications Committee, who were very familiar with the telegraph, felt that remote messaging was very novel, had great potential and was very promising. However, it was not much different from the telephone and telegraph at present. Before the systems for receiving and automatically processing various types of data became popularized, it did shock people, but it was not very profound.

However, the leaders of the Postal Communications Commission still expressed great interest in the speed of message communication. With the operator's fingers flying, a message of more than 100 words was edited and sent to the destination within one minute.

This efficiency, leaving aside the time it takes to establish a channel, and only considering the speed of writing, sending and displaying, is basically more than five times that of a telegram.

After all, message communication has greatly simplified the process of telegram editing, sending, copying and translating. What you see is what you get. It can be sent immediately after editing and the recipient can receive it immediately.

Also, computers don’t get tired, but people do.

The entire process of telegraph, the workload of message communication, and the manpower required are obviously much simpler for the latter.

The leader of the Postal and Communications Commission laughed and said, "The only regret is that this news still needs to be copied down from the screen manually, otherwise it could be faster."

Gao Zhendong immediately laid out a bait: "I have already completed the original design of a printer that can automatically print text content on a computer onto paper. Together with the Computing Institute, I have organized relevant personnel and handed it over to the Computing Institute for specific implementation. There should be good news within a few months."

When the leaders of the Defense Work Committee and the Postal and Communications Committee heard Gao Zhendong's words, they looked at each other in surprise. Comrade Zhendong's series of actions were really dazzling.

"Really?" Although the leader of the Defense Work Committee knew that Gao Zhendong would definitely not brag in this situation, he still asked this question. The main reason was that Gao Zhendong's actions were too fast, as if everything had been planned since DJS-59.

Gao Zhendong nodded: "Now the most difficult part, the print head, has been completed with the help of our senior technicians and the computing institute. The prototype is basically working."

The leaders of the Defense Work Committee were very satisfied with Gao Zhendong's answer. What they were satisfied with was not the progress of the printer, but the fact that Gao Zhendong was obviously using his ability to lead by example and drive all relevant forces to move forward together.

A single tree cannot make a forest; only when everyone is well can there be true well-being.

After listening to Gao Zhendong's words, the leaders of the Postal and Communications Commission became even more convinced about using computers + modems to replace some telegrams. This thing is good, at least it won't be so difficult for people to achieve the effect of sending telegrams.

Although it is very expensive, the price of hundreds of thousands is not unaffordable for some important nodes. The thing called "printer" that Gao Zhendong just mentioned can be regarded as the last piece of the puzzle for data display.

Although he did not have a systematic concept of information and data, he knew that the smooth flow of information was crucial to all walks of life. Even when making plans, the more comprehensive the data, the more scientific the plan.

In fact, what he didn't know was that when the single-board computer that Gao Zhendong was working on came out, it would be the last piece of the puzzle, and it would not only be for telegraphs, but also for many other things.

The leader of the Defense Work Committee patted Gao Zhendong on the shoulder and said, "Comrade Zhendong, thank you for your hard work."

Gao Zhendong subconsciously puffed out his chest: "Serve the people!"

This reminded the leaders of the Defense Work Committee of Gao Zhendong's background, and they burst into laughter.

At this point, the experiment progressed to file transfer.

If messaging communication felt novel to the two leaders, then file transfer was revolutionary.

When they saw that a 3-word Chinese character file was transmitted in 17 minutes and 0 seconds, and quickly received confirmation from the Institute of Operations that the bit error rate was %, they realized what Gao Zhendong meant by "too convenient and easy to be exploited" in the previous meeting.

After all, the parameters seen at the meeting are all text, not intuitive. Only by being there in person can you have a real feeling.

Ten thousand words, how long would it take to send them by telegram?

According to the Chinese character encoding scheme that Gao Zhendong worked out with his colleagues, one Chinese character occupies two bytes, and 20 characters is about k bytes. To be honest, in Gao Zhendong's opinion, it takes three minutes to send this amount of data, which is really unbearable.

After all, the modem has a speed of 1200bps, which means it can only transmit 0.1k bytes per second. 20k bytes takes about 200 seconds. In Gao Zhendong's previous life, 200 seconds, if 5G was running at full speed, would be enough to watch a movie, and it would be a high-definition and high-bitrate movie.

But for those who were experiencing the magic of network communication for the first time, it was like the beginning of the universe. It happened so fast!!

At the meeting, units such as bps, byte, and kb were not intuitive enough, and some people were even confused. However, here, intuitive experiments told everyone: your imagination cannot keep up with the reality of technology.

Amid everyone's surprise, the leader of the Defense Work Committee turned around and looked at Gao Zhendong: "Can this thing automatically encrypt the transmitted data?"

He thought a lot. This thing has a very broad prospect. Gao Zhendong smiled and said, "Yes, I have designed an encryption method that can automatically encrypt before sending and automatically decrypt at the receiving end. However, I have only completed the mathematical algorithm principle and have not yet implemented it in the program."

What Gao Zhendong was thinking of was the classic symmetric encryption standard DES, an encryption algorithm that uses a 56-bit key and was established in the United States in 77.

Although 56-bit keys will no longer be secure in the future, at this time, the amount of computing power required to crack them is astronomical for existing computers.

If you want to crack the key, it is much more reliable to look through the trash can to find the commonly used key that may have been leaked than to traverse and crack it. This is the legendary "social engineering attack".

Imaginary hacker: fingers flying, typing frantically on the computer.

Real-life hack: rummaging through trash cans.

As for the more secure 3DES and AES, Gao Zhendong was prepared to take it slow, as the amount of computation was much larger and taking a big step would easily lead to failure. As for RSA, that was even further away.

And one advantage of DES is that once the computer has sufficient computing power, it is easy to transition to the more secure 3DES.

The leader of the Defense Work Committee asked, "How is the safety?"

Gao Zhendong said: "If the key is managed well, it is quite safe."

The leader of the Defense Work Committee's eyes lit up: "Okay! Make this thing as soon as possible, I'll give you three months!"

Gao Zhendong shook his head.

"The time is too short? Are five months enough?"

Gao Zhendong shook his head again and pointed a finger.

"One year?"

"one day!"

Everyone at the scene opened their mouths wide, with an expression that said "Do you want to confirm what the fuck you are talking about?"

The leader of the Defense Work Committee had a serious expression on his face: "One day? Isn't that a bit hasty?"

What I mean is, Zhendong, take it easy, you have to be responsible, and change your words quickly.

Knowing that what he said was a bit sensational, Gao Zhendong quickly explained for everyone's physical and mental health: "It's just one day. The difficult part is the mathematical algorithm, which I have already completed. The only thing left is programming. And this thing is actually a computer doing repetitive tasks over and over again. The program is not complicated. One day is enough."

After thinking for a while, he added: "Of course, the time required to go through the process of final use is not something I can control."

The DES program itself is really not complicated. If Gao Zhendong wrote it himself, even if he only used the standard library and did not use any third-party library, it would only take a few hundred lines of C language code.

In fact, the core parts of many software may not be very large in scale. The large ones are often some useless functions, or things that serve software developers.

Gao Zhendong couldn't help but think of the music app on his mobile phone in his previous life. He didn't download any songs, but it had more than 3G of space. He really didn't know what these 3G were.

Therefore, Gao Zhendong did not plan to delay, as delaying would disrupt the rhythm of his other work. It would be better to cut the Gordian knot and finish it as soon as possible.

And it's not just the program, the algorithm description and standards are all written out together, so that others can use it after throwing it out without you having to take care of it yourself.

As for how to use it, the relevant personnel will take care of it, such as the leaders of the Defense Work Committee.

Gao Zhendong feels that he is now like an Up master on a certain website, digging holes everywhere. The previous ones have not been filled yet, and the later ones are being dug. There is no other way, there is too much knowledge and time is running out.

On second thought, I am much better than some Up masters. At least I don't delay. Although there are many pits, as long as I dig a pit, I will fill it. For example, this one, I dug it and filled it right away.

Well, that's okay.

Seeing that he was so confident and explained the reason for his confidence, the leaders of the Defense Work Committee felt relieved.

He had seen Gao Zhendong fire fireworks many times, but he had never seen him fire a blank. He asked that question just now only out of concern and protection.

Since Gao Zhendong has explained it so clearly, there should be no problem.

He thought for a moment and said to Gao Zhendong, "Well, in that case, I'll have someone contact you as soon as possible to discuss the details and technical issues with you, and then you can write it."

(End of this chapter)