Hardware security for embedded devices: TPM and TrustZone

Software-only security has a weak foundation if the device cannot protect keys or prove what firmware is running.

This is an English DEV.to draft based on a Silicon LogiX technical article. The canonical source is linked at the end.

Why it matters

Connected products increasingly need a hardware-backed trust anchor for identity, updates and data protection.

TPMs, TrustZone and secure enclaves solve related problems, but they are not the same tool.

Architecture notes

• A TPM is useful for key storage, attestation and measured boot in Linux-class systems.
• ARM TrustZone separates secure and non-secure worlds, enabling protected services on compatible MCUs and SoCs.
• Secure enclaves or security elements can isolate credentials and cryptographic operations from the main application.
• The firmware architecture must define which assets are protected and who is allowed to access them.

Practical checklist

• [ ] Identify secrets: device identity, TLS keys, update keys, user data and calibration data.
• [ ] Design provisioning for manufacturing, service and replacement.
• [ ] Tie secure boot, key storage and OTA verification together.
• [ ] Plan what happens when a key is rotated or compromised.
• [ ] Document the trust boundary clearly for audits and maintenance.

Common mistakes

• Adding a security chip without changing the firmware threat model.
• Protecting keys but leaving debug access open.
• Forgetting recovery and ownership transfer flows.

Final takeaway

Hardware security is not a component purchase. It is an architecture for identity, trust and lifecycle control.

Canonical source: Hardware security for embedded devices: TPM, TrustZone and secure enclaves

If you build embedded, IoT or firmware products and want a second pair of eyes on architecture, update strategy or security, Silicon LogiX can help turn prototypes into maintainable systems.