Ambimat Group Ambimat AmbiSecure eSIM Initiative Engineering Blog Ahmedabad · India · Est. 1981
FIDO2 Applet / Nano SIM

AmbiSecure FIDO2 Nano-Card Applet

A FIDO2/CTAP2 applet that runs inside a nano-card (4FF) secure element or a solderable MFF2 module. The same trust boundary used in a phone or smart card, repurposed as a phishing-resistant authenticator — for OEM device identity, embedded systems, and identity programmes where adding a separate token is not an option.

FIDO2CTAP2Nano SIM (4FF)ECC P-256Hardware-backed
AmbiSecure FIDO2 nano-card applet — FIDO2 over a nano-SIM secure element
Why a embedded secure-element authenticator

The trust boundary already lives in the device. Re-use it.

Hardware boundary, no extra chip

FIDO2 keys stay inside the SIM's secure element — the same boundary that already protects telecom credentials. No new physical part, no new BOM line.

Roaming or embedded

Removable in a SIM tray for cross-device roaming, or soldered (eUICC variant) as an always-present platform authenticator. Same applet, two operating models.

Origin-bound by protocol

FIDO2 binds every credential to the relying-party origin at the protocol layer. Phishing pages on look-alike domains cannot trigger a valid signature.

Telecom + identity convergence

Operators and OEMs can ship a single piece of silicon that handles network access AND phishing-resistant authentication for the workforce or subscriber base.

Resident credentials

Up to a dozen discoverable credentials per applet instance, depending on chip variant. Username-less FIDO2 flows work out of the box.

Standards-aligned

Implements FIDO2 over CTAP2.1 with ECC P-256, signed authenticator data, and a per-instance AAGUID. Attestation runs through the FIDO Metadata Service path.

Specifications

What is in the applet.

Form factorISO/IEC 7810 4FF nano SIM, 12.3 × 8.8 × 0.67 mm. Optional eUICC variant for embedded deployments.
InterfacesISO/IEC 7816 contact (T=0 / T=1). NFC (ISO/IEC 14443 Type A) when paired with an NFC-equipped host device.
ProtocolsFIDO2 (CTAP2.1); FIDO U2F (CTAP1) fallback.
CryptographyECC P-256 (FIDO2); SHA-256; on-applet key generation; signed attestation.
Resident credentialsUp to 12 discoverable credentials per applet (chip-variant dependent).
Operating systemJavaCard 3.x on a Common Criteria EAL5+ secure element from a partner vendor.
PersonalisationLoaded via GlobalPlatform SCP03. AAGUID injected at personalisation. Compatible with our Multi-Card Applet Loading Tool.
AttestationPer-batch attestation certificate chain signed by an AmbiSecure issuance CA; ready for the FIDO Metadata Service entry.
VolumesEngineering samples on request. Production volumes by the reel for telecom/OEM.
Lifecycle

From silicon to credential.

A embedded secure-element FIDO2 authenticator is only as trustworthy as the line that personalised it. Here is the canonical flow.

01

Chip

Common Criteria EAL5+ secure element from a partner vendor.

02

Applet load

FIDO2 applet loaded over GlobalPlatform SCP03 in a controlled facility.

03

Personalise

AAGUID injected, attestation certificate provisioned, secure-domain locked.

04

Provision

Telecom profile or OEM device-identity profile written alongside, sharing the same SE.

05

Issue

Shipped to the operator / OEM line as a finished SIM.

Pilot a embedded secure-element FIDO2 authenticator.

Tell us your target form factor (removable nano SIM, soldered eUICC), expected volume, and target host platforms. We can ship engineering samples in 6–8 weeks.

Request a pilot