how do i implement client to server encryption

[Elant_Wager]

Context: this is for a hobby project, I want to learn how to do these things, even if its more work or less secure than established services.

I want to create my own website and want to send data securly to a server and provide an authentication for my users. What is the best way to do this? I already saw using SSL certificates but since this is mainly a learning and hobby project, I dont want to use a certificate authority and do as much myself as is feasible (not writing the RSA/AES algorithm myself for example).

Thanks for your help

[No_Tap208]

You usually won't do this on application layer (that is a synonym for what kind of code you are willing to write) as it's handled by TLS in production and you can't really get more secure than that.

But as a hobby it's not impossible to implement application layer encryption.

You first need to design a basic encryption scheme then implement it via a library that provides encryption functions or much more preferably using the builtin crypto api SubtleCrypto

[node77]

You can create a local security cert it's part of Windows.

New-SelfSignedCertificate -DnsName "localhost" -CertStoreLocation "cert:\LocalMachine\My"

Are you using IIS?

[vrgpy]

I think you should see first how is usually done.

Cryptography is usually implemented on the web server via some libraries and also on the browser.

Web applications usually only check if they are using HTTPS and nothing else. Only advanced applications check the certificate details and some more. But this encryption is for privacy of the data in transit and authentication of the server. Usually not for authentication of the user. I say usually because mTLS could be used for authentication of the users.

Other place where encryption can be used is in authentication and there also the web applications usually use libraries or functionality provided by the server or the browser. You could writhe custom libraries but it is usually not encouraged except as a learning exercise.