Series 2 Device Security Features#

Protecting IoT devices against security threats is central to a quality product. Silicon Labs offers several security options to help developers 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 Series 2 products that included a Secure Engine. The Secure Engine is a tamper-resistant component used to securely store sensitive data and keys, and to execute cryptographic functions and secure services.

On Series 1 devices, the security features are implemented by the TRNG (if available) and CRYPTO peripherals.

On Series 2 devices, the security features are implemented by the Secure Engine and CRYPTOACC (if available). The Secure Engine may be hardware-based, or virtual (software-based). Throughout this document, the following abbreviations are used:

• HSE: Hardware Secure Engine

• VSE: Virtual Secure Engine

• SE: Secure Engine (either HSE or VSE)

Additional security features are provided by Secure Vault. Three levels of Secure Vault feature support are available, depending on the part and SE implementation, as reflected in the following table:

Notes:

1. The features of different Secure Vault levels can be found in https://www.silabs.com/security.

2. The x is a letter B, F, M, or Z.

3. Unlike other VSE-SVM parts, the EFR32xG27C device has a built-in PUF.

Secure Vault Mid consists of two core security functions:

• Secure Boot: Process where the initial boot phase is executed from an immutable memory (such as ROM) and where code is authenticated before being authorized for execution.

• Secure Debug access control: The ability to lock access to the debug ports for operational security, and to securely unlock them when access is required by an authorized entity.

Secure Vault High offers additional security options:

• Secure Key Storage: Protects cryptographic keys by “wrapping” or encrypting the keys using a root key known only to the HSE-SVH.

• Anti-Tamper protection: A configurable module to protect the device against tamper attacks.

• Device authentication: Functionality that uses a secure device identity certificate along with digital signatures to verify the source or target of device communications.

A Secure Engine Manager and other tools allow users to configure and control their devices both in-house during testing and manufacturing, and after the device is in the field.

Silicon Labs strongly recommends installing the latest SE FW image on Series 2 devices and updating to the latest GSDK to mitigate security vulnerabilities. The latest SE FW image can be found in this Windows folder for GSDK v4.x:

C:\Users\<PC USER NAME>\SimplicityStudio\SDKs\gecko_sdk\util\se_release\public

Refer to AN1222: Production Programming of Series 2 Devices for guidance on the SE firmware upgrade procedure. The latest SE firmware shipped with Series 2 devices and modules (if available) at the time of this writing are listed in the following table:

:::custom-table{30%,}

:::custom-table{30%,}

:::custom-table{30%,}

In support of these products Silicon Labs offers whitepapers, webinars, and documentation. The following table summarizes the key security documents:

:::custom-table{30%,50%,20%}