CSR Formats, X.509 Standard, and more...

Sat, 02 May 2026 07:07:33 +0530

What are X.509 certificates? Link to heading

A X.509 is the standard certificate format of signed certificate which contains details like the server’s public key, the domain name it’s valid for, who issued it, how long it’s valid etc.

You don’t really need to memorize the structure, but the idea is that every certificate on the internet follows the same blueprint, so browsers know exactly where to look for things like the public key, issuer, and signature. It’s what makes the whole system interoperable.

Refresher on Symmetric vs Asymmetric Encryption

Sat, 18 Apr 2026 18:23:33 +0530

Before we jump into TLS, certificates, and all the “why is my browser yelling at me” stuff… we need to get one thing straight:

How encryption actually works underneath?

There are two types of encryption you’ll see everywhere:

Asymmetric
Symmetric

Symmetric Encryption (Same Key, Both Sides) Link to heading

This is the simpler one. This is where you and I share a secret key.

I encrypt using that key
You decrypt using the same key

Encrypt(message, key) -> ciphertext
Decrypt(ciphertext, key) -> message

It’s useful because it’s really fast—like, very fast—and that makes it great for handling large amounts of data without slowing things down. Also note that in context of this series, it typically is used after a connection has already been established.

Symmetric on DevLogs

CSR Formats, X.509 Standard, and more...

What are X.509 certificates? Link to heading

Refresher on Symmetric vs Asymmetric Encryption

Symmetric Encryption (Same Key, Both Sides) Link to heading