emSecure & emBoot-Secure

SEGGER emSecure provides digital signature verification for embedded systems that must authenticate firmware, configuration data, or any binary payload before allowing it to execute or take effect. Using asymmetric cryptographic signatures, emSecure ensures that only firmware signed by the authorized private key can pass verification on the target device, protecting deployed products against unauthorized modifications, counterfeit firmware, and supply chain injection attacks. For Indian OEMs shipping connected devices into regulated markets, emSecure provides the cryptographic foundation required to demonstrate firmware integrity compliance.

Supported Algorithms

Category	Algorithm	Key Sizes / Curves	Purpose
Digital Signatures	RSA-PSS	1024, 2048, 4096 bit	Firmware image authentication
	ECDSA	NIST P-256, P-384, P-521	Compact signatures for constrained devices
	EdDSA (Ed25519)	Curve25519	High-performance signature verification
Hash Functions	SHA-256	256-bit digest	Firmware integrity check
	SHA-384 / SHA-512	384/512-bit digest	Extended integrity verification
Key Management	Asymmetric key pairs	RSA or ECC	Offline signing, on-device verification

Secure Boot with emBoot-Secure

emBoot-Secure extends this capability into a complete secure boot and firmware update solution. At power-on, emBoot-Secure validates the firmware image signature before transferring execution, establishing a chain of trust from the boot ROM through the application code. The integrated firmware update mechanism supports field updates with automatic rollback protection, if a new firmware image fails validation or does not boot successfully, the device reverts to the last known-good image, preventing devices from being bricked by interrupted or corrupted updates in the field.

Air-Gapped and Offline Operation

Watch the SEGGER emSecure introduction

The entire emSecure and emBoot-Secure stack operates on-device without requiring network connectivity for signature verification, making it suitable for air-gapped industrial controllers, automotive ECUs, and military-grade systems. Key generation and signing happen offline using standard tools, while the lightweight on-device verifier fits within the resource constraints of Cortex-M class microcontrollers. Royalty-free licensing means that securing every unit with a verified boot chain adds no per-device cost to the bill of materials.