---
title: IoT Authentication Guide
description: Implementing hardware-based and token-based auth for IoT devices using C++.
category: authentication
tags: iot, cpp, embedded
---
# IoT Authentication

In the realm of IoT, authentication often relies on Hardware Security Modules (HSMs) or TPMs.
Use certificates stored in secure elements rather than shared secrets.

```cpp
// Pseudocode for TPM-based auth
TPM_Context ctx;
TPM_Init(&ctx);
if (TPM_VerifyIdentity(&ctx, certificate_blob)) {
    // Authenticated
}
```

Minimize the use of bearer tokens. Prefer mutual TLS (mTLS) for device-to-cloud communication.
Rotate certificates frequently and use a robust revocation list (CRL) or OCSP.
Ensure your bootloader is locked and uses Secure Boot to prevent unauthorized firmware.
