The new way to communicate using light.

"Propagation of light pulses with intermodal dispersion in multimode fibers, MMF. Words are mapped to different frequencies (different colors), the optical pulses are stretched into different temporal dispersion curves. This allows for the identification of the pulse frequencies at the receiver, thereby enabling the reconstruction of the input words. Credit: Gao, Z., Jiang, T., Zhang, M. et al." (ScitechDaily, Scientists Just Taught Light to Transmit Meaning – And It’s Revolutionizing Communications)

There are many ways to make light-based communication systems. Normally, we think that the light flashes mean 0 and 1 in a laser communication system. But the 0 and 1 can be two different wavelengths. That means the flash of red can mean 1, and the flash of green can mean 0. This is a useful tool for binary data transmission. But there is one way to transmit data by using light that we don't usually mention. 

In that version, a single wavelength means a single word. The system must only give serial numbers for light- or radiation flashes. Then the receiver can put those flashes back into a certain order. That means red can mean "if", green can mean "and" etc. Researchers can also use radio waves in the same way as lasers. And the point of the CCD camera those people can put a radio spectral scanner. 

There are approximately 600000 words in English. Some people might think to use that kind of data transmission, the system requires 600000 wavelengths. The system can send those messages by blinking the colored lasers in the order that gives words to the receiver. If one color carries one word that makes the system immune to disturbance. 

"Experimental system. a, encoding: Each word is mapped to an optical frequency according to the encoding table. b, Schematic of the experimental setup. c, decoding: Recognize each dispersion curve as the corresponding frequency using the fingerprint dictionary, and then reconstruct the words based on the encoding table. d, implement sentiment analysis using a deep learning model. Credit: Gao, Z., Jiang, T., Zhang, M. et al." (ScitechDaily, Scientists Just Taught Light to Transmit Meaning – And It’s Revolutionizing Communications)

The problem is that. Language advances all the time. And the system requires very advanced and complicated transmitter-receiver pairs. But theoretically is possible to create a CCD camera that pixels can separate 600,000 frequencies. And, a transmitter can also have the ability to send 60000 separated frequencies. 

And that means the system must have flexibility. If the system uses the English alphabet. It needs only 52 frequencies for the letters. There are 26 capital and 26 lower cases. And other frequencies for numbers and special marks like brackets. Or the sender can use the words to send numbers. But that creates limitations in massages. 

The system can use red as "A" and the light flashes can involve data which place the certain letter takes in the words. That thing is hard to jam. 

So it's immune for the outcoming errors. But otherwise, it's easy to break. 

The system can also encode lots of words in one wavelength. There can be hundreds of words encrypted in certain colors. The system must only send the serial number of the word that the system sends. This kind of system is more complicated to break. That thing makes this thing more vulnerable to disturbance. 

https://scitechdaily.com/scientists-just-taught-light-to-transmit-meaning-and-its-revolutionizing-communications/

There is quite simple math behind the two-stage encryption.

When we log in to some internet services. We see the famous screen, and there are two lines. The upper line is the normal login. Where we write things like Email or username. That username is called a public key.  The fact is that the username is also non-public. That means that is hidden from other users.  

Below that line is the space for the password.  That is called a "hidden" or non-public key. In that kind of encryption. The user first logs in to the system using the public key. That tells the system that the user has the right to use the system. 

Then the passphrase is the key to the step in the system. This is the key procedure in modern cryptology or encryption process. When the system wants to encrypt information. The system first sends the information who is the sender. Then that system encrypts data and sends it to the receiver. And if the receiver has the right key, that thing allows the receiver to open the message. 

Encryption allows the receiving system to select the information that it uses. That thing makes it possible to transmit information by using the same frequency to multiple receivers. And without that public key. The system cannot find the right receiver from the network. In the network, routers and switches use the public ID to route the message to the right address.

In the RSA encryption process. The system uses long binary- and quantum binary decimal numbers to secure information. The thing that secures information is the selected binary numbers. The formulas that the system uses are always the same. There can be different formulas or calculation series in the encryption process. But the process itself is similar all the time. 

The weakness of that encryption is this. The receiving system must know the formula and binary numbers that the transmitting system sends. The public key requires that the receiver knows what algorithm or formula it must use in the decryption process. And then another thing is that the receiving system must know the binary numbers. That transmitter is used in encryption.

And why do those systems require binary numbers?  It's possible to divide The binary number by using only that number itself. That denies the ability to use other numbers. Then the binary number itself opens the message. The problem is that the user must set the right and the same binary numbers to the transmitting and binary systems. 

The encryption process is based on the ASCII codes. The encryption system multiplicates and divisions those codes by using binary numbers. The system can make multiple divisions and multiplications. The receiving system must make those calculations backward so that it can open the message. The math behind the encryption is very simple. 

It contains divisions, multiplications, and maybe plus-minus calculations. That makes it very simple and effective. The problem is that this type of encryption is old-fashioned. That encryption was made in the late 70's and the short algorithms are a piece of cake for the fast, high-speed supercomputers. Quantum computers can make the code braking in seconds, even if the binary computers generate those numbers for years.