Chapter 1020: We must guard against Gao Zhendong
The comrades from the Military Communications Institute did as they were told. This is the extent of what they could say about the Internet. They could not bring up anything deeper. Moreover, Teacher Gao had already said everything that needed to be said, so there was nothing more to say.

We will have to wait until we gather comrades from the Postal and Communications Commission, the Communications Institute, and the Beijing Institute of Technology to talk it out in more detail.

Gao Zhendong did not participate much in their subsequent discussion, at least not in a long speech. He mainly just interjected a few words at appropriate times and participated in the discussion and resolution of some details.

These are all command requirements and functions. It's okay for him to give some advice and suggestions on these things, but the main ideas still have to come from the troops.

Gao Zhendong doesn't think he can do everything by himself. He wants to get involved in everything and has the illusion that he is incapable.

The meeting lasted for three days. After all, this is a very large thing and it cannot be covered in one or two days.

Gao Zhendong spoke a lot about Internet issues on the first day, but he basically kept this up afterwards. Those who preside over the command system must be command personnel, just like those who engage in cultural work must have culture.

However, on the last day, the commander's complaints caught his attention.

"There is a rather obvious and prominent problem now. Our key management work is becoming more and more onerous. If you want to say it is a big deal, it is not that big, but if you want to say it is a small matter, it seems to be really inconvenient." This is a comrade from the army and from the command center.

After all, the terminal only needs to use the key in its hand, but the command center has more things to consider.

"Tell me more specifically?" The chief engineer of the National Defense Committee was very interested in this matter. As the center of the national defense system and the agency responsible for the management and distribution of high-level keys, their feelings on this issue might not be any easier than those of the comrades in the command center.

"Boss, you may also be responsible for related work, so you should be able to feel that it is okay for ordinary terminals, but for other nodes of a certain level, our keys must be different and correspond to different nodes."

In their current environment, different nodes must be given different keys, so that each node's key can only be used to decrypt its own data and cannot be used to decrypt other node data.

After all, nodes are very likely to be lost. Once lost, using the same key means that this node can decrypt all node data, which is a major flaw in confidentiality and security.

"And the problem doesn't end there. When we need to change the key, it becomes even more troublesome. We have to distribute and notify them one by one, and we have to keep a lot of different keys at the command center, and they must strictly correspond to the high-security terminals and nodes."

Strictly speaking, it’s not that this thing cannot be managed, but it’s very troublesome to manage. And once the nodes need to communicate directly with each other, things become serious.

A comrade from the Military Communications Institute said, "Our command center's data forwarding system has a key management function. I don't think this is a big problem."

"Yes, there is, but the problem now is that as the number of nodes communicating with each other increases, the problem becomes more troublesome."

Each node must save the communication keys of all other nodes. When each node changes its key, it must notify other nodes one by one.

If there are N high-security nodes in the network, it means that once the time comes to change the key, the nodes will have to communicate N*(N-1) times in total. This number of communications is not a big deal in the high-bandwidth network of decades later, but in this communication network of today, almost nothing can be done for a long time, just sending keys to each other.

"This is also a necessary key management process. There is no other way. We can only suppress it through means such as staggered distribution." The comrades from the Military Communications Institute thought for a long time and said that they were powerless for the time being.

When Gao Zhendong heard this, he raised his hand to indicate that he had something to say.

"Comrade Zhendong, do you have any suggestions?" said the chief engineer of the Defense Work Committee.

A considerable number of comrades here know where the current communication system's National Secret-1 encryption algorithm came from. He knows it even more clearly that it came from Gao Zhendong, and he solved the problem quite quickly, resolving the data encryption problem in just one day.

Therefore, Gao Zhendong’s opinions or suggestions are very important in this matter.

Gao Zhendong nodded: "Well, there is a way to do this. When updating the key, the number of communications can be reduced to N. This way, your distribution management will be much more convenient. However, this method requires a lot of computation and can only be used on important nodes with high-computing processors for the time being."

When the comrades heard Gao Zhendong's words, they immediately became extremely excited. Is there such a good thing?

Anyone who has studied elementary school mathematics knows how big the difference is between N and N*(N-1), and the larger N is, the greater the difference is.

It can be said that Gao Zhendong’s statement can completely solve this problem.

"Teacher Gao, there is such a technique? Please tell me in detail."

Gao Zhendong smiled and said, "It's actually very simple. As long as it is used for encryption keys and cannot be used for decryption, does it mean that each node does not need to distribute different keys to other nodes separately?"

Not to mention other comrades, even the comrades at the Military Communications Institute were confused by this and it took them a long time to digest it. "Teacher Gao, what you mean is that as long as the encryption key cannot be used for decryption, then there is no need to worry about other nodes using the encryption key to decrypt data that does not belong to them?"

To be honest, when they said this, the comrades at the Military Communications Institute themselves were confused, as if there was a layer of fog in their heads.

Gao Zhendong nodded and shook his head: "Actually, what I mean is that no one can decrypt the data with the encrypted key, not only other unrelated nodes, but also the two parties in the encrypted communication themselves."

The comrade from the Military Communications Institute digested it for a while before he felt that it made sense: "If this is true, then there is no need to prepare a different key for each node of the same level. It is enough to distribute a unified key by broadcasting. But... this..."

At this point, he swallowed his saliva, which was a physiological reaction to being too stimulated. "This is impossible, right? The current encryption and decryption algorithms are reversible. If a key can be used for encryption, it must be used for decryption. There is no way around it."

He racked his brains but couldn't figure out how to make this happen.

This is pure mathematics. If Gao Zhendong had not been standing at the technological level of several decades later, he would not have been able to figure it out himself, let alone the comrades from the Institute of Military Communications who had just come into contact with this concept.

Gao Zhendong smiled and said, "Of course this algorithm won't work now. It's a symmetric encryption algorithm. But what I just said is an asymmetric encryption algorithm."

"Asymmetric encryption algorithm?" The conversation at this time was completely a fight between gods. None of the other comrades could understand it, and even the comrades from the Military Communications Institute themselves did not understand it very well.

"Yes, as the name implies, its encryption and decryption are asymmetric, and the encryption key and decryption key are different. Don't worry about the specifics of this algorithm, just think about whether this algorithm can solve the problem you mentioned now?"

Seeing that Gao Zhendong did not introduce any further technical details, the two giants of the Defense Work Committee who were always ready to interrupt felt relieved. It seemed that Comrade Zhendong's experience was becoming more and more rich.

In fact, they are overthinking it. The most ridiculous thing about this kind of algorithm is that even if you know all the details, you still can't decrypt it.

Even those who have poor math skills may not understand after listening, and even if they understand, they may not be able to do it, and even if they do know, they may not be able to write it.

The comrade from the Military Communications Institute thought for a long time and nodded: "It can solve our problem. It is true that N nodes only need to broadcast and distribute once each, a total of N times. In this case, there is no requirement for the security of the key transmission process. Even plain text transmission is acceptable."

They are still very sharp. In fact, this is the core reason for the emergence of asymmetric encryption algorithms.

——There is no need to consider the security of key distribution, and it is even okay to keep shouting with a loud speaker.

As for benefits such as reducing the number of key distribution times, they are all derivative products of this core capability.

Gao Zhendong laughed and said, "That's fine. You don't have to worry about this problem. Come to me tomorrow and I'll give you an algorithm that I guarantee will work well. By the way, I'd like someone who's good at math. It doesn't matter if the software is good or not, as long as you're good at math."

Gao Zhendong has more than one asymmetric encryption algorithm in his hands, including RSA based on large number decomposition and the previous national secret SM-2 based on elliptic curve. As for which one to use and how to use the other one, he already has an idea in his mind.

Another day?
His words reminded his comrades of the feat that Gao Zhendong said he would solve the data encryption problem in one day, and it was really solved in one day. It was a bit like reminiscing about the glorious past.

"Okay, okay. I'll go through the relevant procedures when I get back."

This is an encryption algorithm. To some extent, it is much higher than the level of some specific technologies.

The leader of the Defense Work Committee and the chief engineer looked at each other, and the leader said, "You don't have to go. You can come to the committee to get it when the time comes. The specific personnel, procedures, and matters concerning the mathematicians will be arranged by our Defense Work Committee."

Just after I praised Comrade Zhendong for his experience, he immediately did something weird.

Is this something that the military communication agency can directly take? If I didn't think so much before, and the relevant systems and arrangements for Gao Zhendong were not so perfect, then everything is different now.

Without going into too much detail about the distant past, the chief engineer of the National Defense Work Committee still remembers how excited he felt when the chemists synthesized the super-high-energy explosive called DNTF not long ago.

We must strictly guard against Gao Zhendong, this is the consensus of the Defense Working Committee.

Gao Zhendong touched his head and laughed, thinking that he was too careless.

(End of this chapter)