After eating and drinking, it was time for him to do some work.
There were still a lot of things waiting for him to complete the last part of the Control of Earth and Moon mission chain.
However, just as he was about to get up from his desk, he suddenly heard a knock on his office door.
Lu Zhou thought about his phone call yesterday and guessed who it was. He threw the napkin into the takeaway box and put the plastic bag aside. He cleared his throat and spoke.
"Come in."
The office door was pushed open, and Director Li's familiar face appeared at the door. When he saw the takeaway box on the table, he smiled and was about to say hello, but he couldn't help but look surprised.
"You're eating this for lunch?"
Lu Zhou looked at him strangely.
"Two meat and one vegetable, is there a problem?"
"Uh, no …"
"If not, then let's talk business. I have to go back to the Institute for Advanced Study for a meeting at three o 'clock in the afternoon. It's about the Lunar Orbit Committee." Lu Zhou looked at the time on his watch and said to Director Li, "What did you tell me on the phone yesterday?"
Director Li didn't say anything. He glanced at Wang Peng.
Wang Peng nodded and picked up the takeaway box. He then left the office and closed the door.
Only the two of them were left in the office.
Seeing that there was no one else, Director Li spoke.
"It's about the quantum encryption algorithm."
As soon as Lu Zhou heard about this, he raised his eyebrows and asked with interest.
"Is it good?"
"It's good! It's so good. " Director Li clapped his hands and said with a smile, "The deputy director of the Institute of Information Engineering at the Chinese Academy of Sciences was so surprised that his jaw almost hit the ground …"
Lu Zhou had a bad feeling when he saw this guy's exuberant description.
Every time this old man tried to please him, it was either because he wanted to introduce someone to him or because he had something to ask of him.
"If it's good, why are you still looking for me?"
Director Li smiled and spoke.
"Didn't you say some time ago that after your carbon-based topological quantum processor chip came out, it wouldn't take long for your quantum computer to break through 1,000 qubits?"
Lu Zhou thought for a while and nodded.
"I think I did."
"That's what I'm here for!" Director Li clapped his hands and said, "A few days ago, the department held a meeting to discuss this issue. However, we really lack experts in this area, and we couldn't come up with a solution …"
"Stop, you don't have to explain the cause and effect to me." Lu Zhou raised his hand and stopped Director Li. He sighed and said, "Just tell me what the trouble is."
"It's not a big deal, I just wanted to ask for your opinion." Director Li smiled embarrassedly and asked, "When will this 2000-qubit computer come out?"
Lu Zhou immediately knew what Director Li was thinking. Director Li was worried about the timeliness of the technology.
However, it was inevitable that most people would have this kind of concern.
If the bottleneck from 80 to 500 was so easy to break, then it was hard to say how long the bottleneck from 500 to 1000 could last.
Changing the encryption algorithm was not a trivial matter like changing a password. It involved the reform of the entire communication field, and the hidden social costs needed to be paid were difficult to measure with money alone.
If possible, the relevant departments would naturally want to change the encryption algorithm for a longer period of time.
If the encryption algorithm was updated every three to five years, no matter how tenacious China's financial industry, communications industry, and Internet industry were, they wouldn't be able to withstand this kind of torment …
"Your worries are not unreasonable." Lu Zhou tapped his index finger on the table. After thinking for a while, he said, "But this thing is really hard to say. I can only tell you that the bottleneck of 1,000 qubits can be broken in a short time, but for 2,000 qubits … I can only give you an accurate estimate when the bottleneck of 1,000 qubits is broken. "
Director Li said, "Can't I even make an estimate?"
"It's not a matter of estimation, it's just that it's meaningless." Lu Zhou sighed and said, "If you just want psychological comfort, it's better to ask a fortune teller. From a probability perspective, it's a 50-50 chance anyway. Also … "
Lu Zhou paused for a second and spoke.
"Quantum encryption algorithms are always temporary. N qubits correspond to 2 ^ n states, not 2 times n. In theory, if we only increase the difficulty of the proposition linearly, one day, our encryption methods will not be able to catch up with the speed of our information technology development. "
The office fell into silence.
Director Li repeated Lu Zhou's words over and over again. After a while, he spoke in a serious manner.
After a while, he said, "Then what do you think we should do?"
"We can only solve this problem from the root." Lu Zhou thought for a while and said, "In other words, eliminate the possibility of leakage from communication methods!"
"You mean … quantum communication?"
Lu Zhou nodded with approval.
"Exactly."
Director Li's expression was a little solemn.
"But I heard that quantum communication technology isn't simple, right? Our country is relatively ahead of the curve in this area, and there have been a lot of results, but I haven't seen any signs of this technology maturing. "
"It's normal." Lu Zhou said, "Because the breakthroughs in this field are mainly focused on achieving photon entanglement and enhancing signal strength. But if we want to truly achieve quantum communication, the key is still on the quantum repeater."
The quantum repeater could also be subdivided into two propositions, "quantum memory" and "optimization of the efficiency and storage time of writing and reading quantum states".
These two technical difficulties were mentioned in the DLCZ plan, which used the combination of quantum memory and single-photon channel to suppress attenuation and achieve long-distance quantum communication.
However, because there was basically no major progress in the field of quantum memory, quantum communication could only be achieved within a distance of 100 kilometers, and the requirements for the transmission environment were extremely harsh. This also lost its practical value, to the point that people even doubted whether it could be realized.
"Quantum repeater?"
"Yeah." Lu Zhou looked at Director Li and nodded. He said, "It's not that there is no progress in this area, there is no progress at all. This is the same all over the world … "
The reason why quantum communication could be absolutely confidential was because of the special characteristics of the wave function. Once the photon conveying information was intercepted, any observation would cause the collapse of the entangled state.
In layman terms, if there is a third party C standing in the middle of a phone call between A and B and eavesdropping. No matter what method C used, whether it was using a bug or putting his ear on the wall, as long as C heard a word, A and B would immediately know that the communication was intercepted, and the entire message would become meaningless.
All encryption algorithms, including asymmetric encryption algorithms, were targeted at traditional communication methods. In the face of quantum communication technology, encryption was simply redundant.
This was the so-called "unconditional security"!
After spending about five minutes, Lu Zhou briefly explained the technical difficulties of quantum communication and its advantages over traditional communication methods to Director Li.
Even though Director Li had heard many people talk to him about similar things before, this time, it was Academician Lu's mouth, so the meaning was instantly different.
After listening to Lu Zhou's explanation, he suddenly felt a fire in his heart.
He quickly asked, "Is this' unconditional security 'quantum communication difficult?"
Lu Zhou nodded seriously.
"Honestly, it's not just difficult! It's quite difficult!
"Aside from the parts that you won't understand, you only need to know that this thing is basically the core bottleneck that limits the commercialization of quantum communication technology."
The office was quiet again.
This time, it was quiet for a long time.
Lu Zhou picked up the glass of water on the table and took a sip. He was about to comfort his old friend and tell him not to worry too much. The encryption algorithm could be used for now. When the 2,000-qubit computer came out, there might be new progress in the research of the quantum repeater.
The birth of any new technology needed time to settle. Even though the quantum encryption algorithm he developed wasn't particularly brilliant in his opinion, it wouldn't be a problem to put up with it for a while.
However, just as he was about to speak, Director Li couldn't help but take a step forward. He asked anxiously.
He anxiously asked, "Then, that quantum repeater, can you handle it?"
Lu Zhou: "…"
You've already exceeded your reading limit for today. If you want to read more, please log in.
Login
Select text and click 'Report' to let us know about any bad translation.
