Now, why use symmetric algorithms if we have to pass the key to the other side? Exactly why use them now? If you can safely work with asymmetric algorithms (RSA ...)? And what gives us if we encrypt the text with a symmetric algorithm , and before transmitting the text, we will transfer the key of the symmetric algorithm to the other side using RSA. And then we transmit the ciphertext and the other side decrypts it.

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    Even when using asymmetric encryption when encrypting large text, it is encrypted using a symmetric method, but the key is encrypted using an asymmetric one. Because asymmetric algorithms are very slow. Actually, the usual ssl (which is based on https) does just that - Mike
  • @Mike, that is, text encryption occurs in a symmetric cipher, and the key is asymmetric. Yeah, that means it gives speed. - Sckoriy
  • At least most applications of asymmetric algorithms do this. Even electronic signatures of documents first calculate some sort of hash, and then they encrypt it in an asymmetric way, in fact signing only the hash itself. It is clear that there are also purely asymmetric and purely symmetric schemes for various applications - Mike

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And what gives us, if we encrypt the text with a symmetric algorithm, and before transmitting the text, we will transfer the key of the symmetric algorithm to the other side using RSA.And then we transmit the encrypted text and the other side decrypts it.

Opened a bike called ...

That's the way they do in real life. The fact is that asymmetric encryption is noticeably inferior in encryption speed (about an order of magnitude), of course, depends on the key length, etc., but in general, the picture is just that.

For example, read how encryption is organized in the password manager from Yandex - asymmetry and symmetry are actively used.