Is there a lightweight messenger, just for two people, with E2E encryption?

Question

linux

There is me and the interlocutor. We need to chat. So that messages are encrypted on clients so that you can explicitly enter the keys of the interlocutors.
Both ip-addresses are not static, nat provider plus a router.
There are also vps.
You only need messages, you don’t need address books, storing messages on the server if the interlocutor is offline, transferring files and other excesses.
No need for a GUI - just the command line, preferably under Linux.

Is there such a thing?

Answer 1

This option might work .

Answer 2

As part of a joke. Buy yourself a HF transceiver. It is unlikely that anyone in our time monitors analog communications, which, like Elusive Joe, no one needs.
Well, if it's serious - then - this issue was decided 20 years ago by one Jewish uncle. Philip Zimmerman. He wrote an open source product called PGP (Pretty Good Privacy) and published it as a book for others to use. I included a set of ciphers with a military bit depth there (it seems there are up to 4096 bits of keys) and made an implementation in the form of console utilities. It is assumed that you will send emails encrypted by this utility. Or through any channel that sends encrypted text messages.

Answer 3

and google for a start??
https://teletype.in/@ht_vbok/HJGdsTYGQ

Answer 4

There is nothing better than Signal or Wire in terms of encryption!
The special services were never able to open them, unlike the same Cart or WhatsApp.
Snowden talked about them in a recent interview, and he himself sits on Signal and advised him if the most complete confidentiality is needed.
Signal is also simple, like three rubles and encryption keys can be manually activated for each contact separately.
Both are available under Linux.
I personally sit on Signal and transplanted all of my people to it.