⚙️ How HMAC Works: Hash + Secret Key
Understand the two-pass hashing process that creates authenticated messages
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0 / 5 completed⚙️ How HMAC Works
HMAC is surprisingly elegant: it's just hashing with a twist! Let's break down the process step by step.
🎮 Interactive Step-by-Step Walkthrough
Watch how HMAC transforms your message and secret key into a signature. Click through each step!
💡 Key Point: The secret key is shared between you and the server, but never transmitted in the request!
🧪 Try Your Own Inputs
💡 Try it: Change just one letter in the message. Notice how the entire signature changes completely!
🔍 The HMAC Formula
🛡️ Why This Design Is Secure
The key stays on your machine and the server. Only the signature travels over the network.
Changing one bit in the message or key completely changes the signature. Attackers can't make small modifications.
Even if attackers see thousands of signatures, they can't figure out the secret key due to hash one-way property.
Practically impossible to find two different messages with the same HMAC signature (for the same key).
⚠️ What Could Go Wrong?
Using short or predictable keys (like "123456") makes brute-force attacks possible.
If the secret key is exposed (committed to Git, logged, etc.), all security is lost.
Older hash functions have known vulnerabilities that can compromise HMAC.