How SSL Certificates Work: A Story of Keys, Trust, and Secure Connections

Kubenatives Newsletter - Edition #13

🏰 The Kingdom of Trust: A Story of SSL Certificates and Encryption

In a great kingdom, the Royal Messenger (RM) is responsible for delivering messages securely between the King and his people. However, spies and impostors roam the land, trying to forge fake letters and steal secret messages.

To solve this, the King orders the creation of a two-key system—a magical set of keys that allows secure communication.

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🔑 The Royal Keys: Public and Private Keys

The Royal Messenger (RM) receives two keys:

1. Public Key (🔵 Blue Key) → A key that everyone in the kingdom can have.

2. Private Key (🟠 Orange Key) → A secret key kept only by the RM.

But how do these keys work? The kingdom has two major problems to solve:

1. How can people send private messages to the RM without anyone else reading them?

2. How can people verify that a message really came from the RM and not from an impostor?

🔹 These problems lead to two types of encryption workflows.

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Scenario 1: Sending Secret Messages (Public Key for Encryption)

A citizen named Alice wants to send a confidential letter to the RM, but she fears that spies might intercept it.

To ensure only the RM can read the message:

1. Alice uses the RM’s public key (🔵) to lock (encrypt) the message.

2. She sends the encrypted letter to the RM.

3. Only the RM, who holds the private key (🟠), can unlock (decrypt) the message.

✅ Even if a spy intercepts the message, they cannot read it—only the RM has the private key to unlock it.

📌 Real-world parallel:

• When you visit a secure website (https://example.com), your browser encrypts information using the website’s public key.

• Only the website’s private key can decrypt your information.

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Scenario 2: Proving Authenticity (Private Key for Signing)