eSIM security — SGP.22, GSMA, and what actually deploys.
eSIM is the new SIM. The trust model is different: instead of a removable card, the credentials live in an eUICC soldered into the device. Remote SIM Provisioning (RSP) replaces the physical card swap. AmbiSecure ships eSIM applets, RSP integration, and the security review across the stack.
The eUICC trust model
An eUICC is a secure element soldered into the device that runs SIM-equivalent applets. Profiles (operator-specific cellular credentials) are downloaded over-the-air from the operator's SM-DP+ server, signed by GSMA-rooted certificates, and installed into the eUICC under SCP03 secure messaging.
The trust model has three roots:
- EUM (eUICC Manufacturer) root — certifies the eUICC hardware.
- CI (Certificate Issuer) root — GSMA-anchored.
- SM-DP+ root — operator-specific profile server.
Each plays a role in the GSMA SGP.22 / SGP.32 mutual-authentication ceremony before any profile material crosses the air.
What we ship
eUICC OS / applets
Profile-receiving applets compliant with SGP.22 (consumer) / SGP.32 (M2M).
SM-DP+ integration
Reference SM-DP+ client and server-side integration. Profile encoding / signing / verification.
eIM proxy (SGP.32)
For M2M deployments where the device cannot reach SM-DP+ directly.
Security review
End-to-end review of an existing eSIM stack: trust roots, profile download, telemetry, rollback resistance.
eSIM ecosystem connection
The Ambimat Group runs a dedicated SIMAuth; eSIM-specific deep technical content lives at esim.ambimat.com. AmbiSecure handles the security half of the stack: eUICC applets, RSP integration, applet personalisation, security review.
Building a connected device with eSIM?
From eUICC selection through SM-DP+ integration to GSMA security review — we ship the security half of the stack.