How to send secure/encrypted POST request between two servers?

Question

PHP

One server (PHP) sends a request to another (NodeJS).
It is necessary:
​​1. Encrypt data
2. Pass the authorization key so that no one else can access the server.
Tell me how and with what you can encrypt / decrypt correctly (what would work in both NodeJS and PHP).
Where can you read?
Would ssh public/private key encryption work? How to implement such a thing?

Answer 1

you can always use your certificate to organize an encrypted connection. This is in both PHP and Node.js. Google - TLS in the context of what you are using.
A good example is the organization of work with APNS (Apple push notifications) servers. You can see how the client is implemented for it, they are both for the node and for the puff.
But since we are talking about POST requests, it all comes down to good old HTTPS with its own certificates.

Answer 2

Why don't you like https for this task?

Answer 3

StartSSL.com issues free ssl certificates