How many steps does it take to get through the quantum cryptography that only you know?
Author/ IT Times reporter Hao Junhui
Editor/ Qian Lifu Sun Yan
In the ancient Greek city-state of Sparta BC, there was a magical round wooden stick, on which a leather belt that could be written was wound according to a special texture, and when the leather belt was untied from the wooden stick, the text on it became a disordered character. In war, if there is no other stick with the same diameter and texture, even if the enemy gets his hands on the belt, he will not be able to get the message of the carry.
Thousands of years ago, the "Spartan Stick" confirmed one point with a simple physical displacement encryption method: information security is an inevitable demand of human society after entering the era of civilization. After a thousand years, people who have entered the digital age are facing more urgent information security guarantees, and the quantum meSis business of China Telecom Quantum Group has given the most secure answer at present.
As one of the important applications of the quantum communication industry, MeSign Quantum has launched large-scale promotion in many cities across the country. In November 2023, China Telecom Quantum Group launched a new "Quantum MeSign" App, which further lowers the threshold for ordinary people to experience quantum communication.
Quantum is a state, not matter
The end of the universe for modern physicists is philosophy.
Since the beginning of the 20th century, Planck proposed the quantization of energy, which has opened the door to the microcosm, and quantum is the most basic note of the universe.
In the microcosm, quantum is not a real substance, but a state. That is, energy does not change continuously, but exists in discrete, non-subdivisible smallest units (quanta of energy). In short, quantum is a state of being, not existence itself.
Quantum entanglement is a state, whether it is photons, electrons, atoms, ions, or Cooper pairs in superconducting circuits, as long as they enter the state of quantum entanglement, they are like a pair of dance partners with a common mind, no matter how far apart, their steps are always tacitly compatible, which is the most poetic interpretation of the microcosm of "the end of the world is next to each other".
Source: Oriental IC
The "Schrödinger's Cat" experiment vividly illustrates the characteristics of quantum superposition states, in which atoms are in a superposition of decay and non-decay before they are observed, and there may or may not be decayed, and cats closely related to the state of atoms should also be in a superposition of life and death: both dead and alive. It is not until you open the box that the atom collapses to a definite unique state.
As one of the three major directions of the second quantum revolution, the cornerstone of quantum communication is the principle of quantum entanglement and quantum superposition. The inability to accurately determine the position and momentum of a particle at the same time means that any unauthorized observation of quantum information will leave traces that can be detected by the legitimate recipient. Quantum entanglement, on the other hand, is a magical association between two or more particles, no matter how far apart they are, the operation of one particle will instantaneously affect the state of the other entangled particles, and this "overdistance effect" provides the possibility of absolutely secure key distribution.
Quantum keys leave "eavesdroppers" with nowhere to hear
In 2003, physicists Jonathan Dowling and Gerard Milburn proposed the concept of the "second quantum revolution", focusing on the application of quantum mechanical principles in a wider range of fields, especially the development of emerging technologies such as quantum computing, quantum communication, and quantum precision measurement.
Among them, quantum communication, especially quantum key distribution (QKD), is currently the most mature quantum secure communication technology due to the small number of bits that need to be controlled, and is the first to enter the industrialization process, and China is the undisputed "leader" in this field.
To put it simply, the basic principle of quantum key distribution is to transmit key information through quantum states (usually polarization states or photon number states). The sender and receiver exchange quantum states and use the properties of quantum mechanics to detect eavesdropping, and if a third party tries to obtain information, both parties immediately detect and discard the key. Eventually, the two parties share an absolutely secure key that is used to encrypt and decrypt the content of subsequent communications.
On the other hand, traditional passwords are usually based on a clear rule, just like a "Spartan stick", as long as the two parties to the encryption and decryption follow the same rules, they can crack the information, but the risk is that once the rules are obtained by someone with intentions, or the "brute-force method" is used to crack the rules, it is difficult to avoid being "eavesdropped". Quantum key generation, on the other hand, takes advantage of the characteristics of quantum randomness, that is, it is irregular, completely physically generated, and has extremely high unpredictability.
A pair of unpredictable keys, an unobservable state, and a security mechanism of "one secret at a time" make quantum cryptography the strongest security shield in the field of communication.
Quantum MeSign can be used without changing the number when changing the card
Although quantum mechanics sounds so "levitating" and quantum keys seem to be as brain-burning as "Schrödinger's cat", in actual use, quantum meSign is as simple as any mobile app.
There are only three steps to make a call to MeSign that only you and I know: the first step is to have a mobile phone with Android system or HarmonyOS system and support NFC function (support OMA protocol), the second step is for both parties to go to the telecom business hall to change a quantum security SIM card, only change the card but not the number, and open the quantum cipher phone service at the same time, and the third step is to download the "Quantum MeSince" App and register.
The function of MeSign is similar to that of ordinary IM tools, which not only supports encrypted calls, but also supports making encrypted videos, creating encrypted group chats, sending encrypted files, pictures, audio and video, and even locations, business cards, emojis, etc. Suppose you send an encrypted message to the other party, you can set different destruction times, ranging from 30 seconds to 5 minutes, and the message will disappear automatically.
Use the Huawei Mate 60 Pro custom terminal to directly dial quantum secret words, open the mobile phone contact interface, next to the conventional small microphone-shaped dialing button, the "shield + small microphone" pattern, is the button to start the "quantum secret phone". After clicking, the mobile phone screen enters the call interface, displaying "Quantum Call Calling", after the other party answers, it will turn to "End-to-end Quantum Encrypted Call", the call experience is the same as that of regular calls, but both parties are required to be Quantum Cryptography users, and relevant services have been opened and cards have been replaced. Other Android users can dial Quantum Secret through the "Quantum MeSign" App.
Every time the user initiates a quantum secret call, the call will randomly select a quantum key in the chip to establish a connection with the platform, verify the identity information, and after the authentication is passed, a new key is generated in real time as the session key, and the authentication key is separated from the session key, and one secret at a time, and it is discarded after use. In this way, even if quantum computing matures in the future, it makes no sense for eavesdroppers to try to brute-force it.
In addition, MeSign Quantum also has a PC version, and the account on the mobile App and the PC side is unified, the data can be synchronized, and the mutual transfer of files between the two ends can also be encrypted. Moreover, the unified identity authentication platform is integrated into the product, which prohibits taking screenshots and screen recording in the application, automatically watermarks, and blocks sensitive words, which can eliminate risks such as identity theft and information leakage.
There are two types of quantum-secure SIM cards: high-capacity cards are 50 yuan each, containing about 130,000 quantum keys, which can generally be used for 4 to 5 years, and small-capacity cards are 4 yuan, containing about 19,200 quantum keys, which can generally be used for 1 to 2 years.