Series 3 Security Features#

Protecting IoT devices against security threats is central to a quality product. Silicon Labs offers several security options to help devel- opers build secure devices, secure application software, and secure paths of communication to manage those devices. Silicon Labs' security offerings were significantly enhanced by the introduction of the Secure Engine on Series 2 products. Series 3 products contin- ue to include and expand upon existing Secure Engine Technology The Secure Engine is a tamper-resistant component used to se- curely store sensitive data and keys and to execute cryptographic functions and secure services.

User Assistance#

In support of these products Silicon Labs offers the following application notes:

Document

Summary

Applicability

AN1190: Series 2 and 3 Secure Debug

How to lock and unlock Series 2 debug access, including background information about the SE

Secure Vault Mid and High

AN1218: Series 2 and 3 Secure Boot with RTSL

Describes the secure boot process on Series 2 devices using SE

Secure Vault Mid and High

AN1222: Production Programming of Series 2 and 3 Devices

How to program, provision, and configure security information using SE during device production

Secure Vault Mid and High

AN1247: Anti-Tamper Protection Configuration and Use (this document)

How to program, provision, and configure the anti-tamper module

Secure Vault High

AN1268: Authenticating Silicon Labs Devices using Device Certificates

How to authenticate a device using secure device certificates and signatures, at any time during the life of the product

Secure Vault High

AN1271: Secure Key Storage

How to securely "wrap" keys so they can be stored in non-volatile storage.

Secure Vault High

Key Reference#

Silicon Labs security implementations use asymmetric key pairs and symmetric keys. The table below clarifies key names, applicability, and relevant documentation.

Key Name

Customer Programmed

Purpose

Used in

Public Sign key

Yes

Secure Boot binary authentication and/or OTA upgrade payload authentication

AN1218 (primary), AN1222

Public Command key

Yes

Secure Debug Unlock or Disable Tamper command authentication

AN1190 (primary), AN1222, AN1247

OTA Decryption key (or GBL Decryption key)

Yes

Decrypting GBL payloads used for firmware upgrades

AN1222 (primary), UG266/UG489

Attestation key aka Private Device Key

No

Device authentication for secure identity

AN1268

AXiP Key

No

Used on Series 3 devices for encryption/decryption and authentication of firmware placed in flash

AN1509

EXiP Key

No

Used on Series 3 devices for encryption/decryption of firmware placed in flash

AN1509