1187 Unbreakable Security
After eating and drinking, it was time to do some work.
In order to complete the last Control of Earth and Moon mission, he had a dozen hurdles to jump over first.
However, just as he was about to get up from his desk, he heard a knock on his office door.
Lu Zhou remembered the appointment he made on the phone yesterday. He threw away his napkins, put away his food container box, and said, âCome in.â
His office door was opened. Director Li appeared at his door. When Director Li saw a food container lying beside the table, he couldnât help but look surprised.
â... Thatâs what you ate for lunch?â
Lu Zhou gave him a strange look.
âYeah, some meat and vegetables, why?â
âUh, nothing...â
âLetâs just talk about business then. Iâm going back to the research institute for a meeting at 3 pm; itâs about the Lunar Orbit Committee.â Lu Zhou looked at the time on his watch and said, âWhat exactly did you want to tell me on the phone yesterday?â
Director Li didnât say anything. He just looked at Wang Peng.
Wang Peng nodded. He picked up the food container bag and left the room.
Only two people were left in the office.
Director Li spoke.
âItâs about the quantum encryption algorithm.â
Lu Zhou was intrigued. He raised his eyebrows and asked, âIs it good?â
âItâs great! Itâs amazing.â Director Li clapped and said, âYou have no idea! After the deputy director of the Institute of Information Engineering saw the algorithm, his jaw was on the floor...â
For some reason, Lu Zhou had a bad feeling about this.
Every time Director Li was nice to him, the old man either wanted something from him or wanted to introduce him to a girl.
âIf itâs so good, why are you here?â
Director Li smiled mischievously.
âA while ago, didnât you say that after the carbon-based topological quantum processor chip comes out, it wonât be long before we can achieve a 1,000 qubit quantum computer?â
Lu Zhou thought for a second and nodded.
âI think I did say that.â
âThatâs why Iâm here!â Director Li said, âThe state held a meeting a few days ago to discuss this issue, but we really need experts in this area. We couldnât find a solution after discussing for a long time, so...â
âPause, you donât need to explain the reason.â Lu Zhou raised his hand and said with a sigh, âYou can just tell me whatâs wrong.â
âItâs not a big problem, we mainly just want to consult your opinion.â Director Li smiled embarrassedly and asked, âWhen will a 2,000-qubit computer come out?â
After hearing Director Liâs words, Lu Zhou immediately understood what he was thinking. Director Li was worried about how long the algorithm would stay secure.
After all, this was an understandable concern.
If it was easy to break the bottleneck from 80 to 500, how difficult could it be to go from 500 to 1,000, then 1,000 to 2,000?
Changing an encryption algorithm wasnât as easy as changing a password. It required a reform from the entire communication field. The hidden social costs couldnât be measured with money alone.
The state obviously wanted to change the encryption algorithm as few times as possible.
If they had to update the encryption algorithm every three to five years, it would cause huge trouble to Chinaâs financial industry, communications industry, and Internet industry.
âYour worries are not unreasonable,â Lu Zhou said as he tapped his finger on the table. After thinking for a moment, he said, âBut this is really hard to say. I can only tell you that the bottleneck of 1,000 qubits will be broken soon. But 2,000 qubits... I have to wait until we achieve 1,000 qubits before I can give you an accurate estimate.â
Director Li said, âCanât you make a rough estimate?â
âI can, but itâs meaningless.â Lu Zhou sighed and said, âIf you just want to feel less anxious, you might as well ask a fortune teller. Also...â
Lu Zhou paused for a second before he continued, âQuantum encryption algorithms are always just temporary. N qubits correspond to 2 to the power of n states, not just 2 times n. In theory, one day, our encryption method wonât be able to keep up with the speed of our technology development.â
The office went silent.
Director Li pondered for a long time. After a while, he asked in a serious way.
âThen, what do you think we should do?â
âWe have to solve this problem fundamentally,â Lu Zhou said after thinking for a while. He said, âWhich means we have to find another means of communication?â
âSo youâre saying... quantum communication?â
Lu Zhou nodded with approval.
âCorrect.â
Director Li spoke solemnly.
âBut I heard that quantum communication technology is not simple, right? Our countryâs research is relatively advanced in this area, yet there arenât many results. I canât see this technology maturing anytime soon.â
âThatâs not a problem.â Lu Zhou said, âThe breakthroughs in this field are mainly focused on achieving quantum entanglement and enhancing the signal strength. The real key to achieving quantum communication is in quantum repeaters.â
Quantum repeaters can also be subdivided into two problemsâthe problem of âquantum memoryâ and the problem of âoptimizing the quantum read and write efficiency and storage timeâ.
These two major technical problems were mentioned in the DLCZ protocol, which used a combination of quantum memory and single-photon channel to suppress attenuation and achieve long-distance quantum communication.
However, due to the little progress in quantum memory, quantum communication could only be achieved within a distance of 100 kilometers. The transmission environment was also extremely harsh. This made it impractical to use; some people even suspected it was impossible to popularize this technology.
âQuantum repeater?â
âYeah.â Lu Zhou looked at Director Li and nodded. He said, âThere hasnât been any progress at all in this area...â
The reason why quantum communication was confidential was because of the special characteristics of the wave function. Once the photon that transmitted the information was intercepted, any observed behavior would cause the collapse of the entangled state, thus destroying the information.
Simply put, if there were a third party C, standing between a phone call among party A and B, no matter what party C did, whether they were using a wiretap or sticking their ear against the wall, the second party C tried to hear something, the entire communication channel would stop.
Asymmetric encryption algorithms and other encryption algorithms were aimed toward traditional communication methods. When it came to quantum communication, encryption was simply unnecessary.
This was the so-called âunbreakable securityâ!
Lu Zhou spent five minutes briefly explaining the technical difficulties of quantum communication and its advantages over traditional communication methods to Director Li.
Even though Director Li had heard people talk about this idea before, hearing it personally from Academician Lu was different.
After he heard Lu Zhouâs explanation, he quickly asked, âIs this unbreakable quantum communication difficult?â
Lu Zhou nodded seriously.
âHonestly, itâs not just difficult, itâs extremely difficult!
âYou just need to know that this bottleneck is completely stopping the commercialization of quantum communication technology.â
The office went silent again.
This silence lasted quite a long time.
Lu Zhou took a sip of water from the cup on the table. He was about to comfort his old friend and tell him not to worry too much. They could use the new set of encryption algorithms for now, and when a 2,000-qubit computer came out, there might be new progress in the research of quantum repeaters.
Any new technology had to take a long time to develop. Even though the quantum encryption algorithm he developed was not particularly brilliant in his own opinion, it was fine for now.
However, when he was about to speak, Director Li spoke first.
âThe... The quantum repeater, can you solve it?â
Lu Zhou: â...â