The Plain English Version
A driver’s license used to be a piece of plastic. Now it can be a credential on your phone — secure, verifiable, and accepted everywhere a physical license is. That credential is called a mobile Driver’s License, or mDL.
For mDL to work in the real world, three things have to come together:
- The phone has to hold the credential securely
- The verifier (a police officer’s tablet, a TSA agent’s reader, a bartender’s device) has to read it — quickly, offline if needed, and with cryptographic proof it’s real
- The whole exchange has to follow a global standard so any phone works with any verifier
Sigil is the engineering that makes all three work together. We make the software that runs on verifiers, the NFC hardware module that turns any device into an mDL reader, and the finished verifier hardware for the businesses and agencies that need to check IDs.
What Sigil Includes
Sigil is three products that work together — sold separately or as a complete system.
| Product | What It Is | Who Uses It |
|---|---|---|
| Sigil mDL Software & SDK | DMVs, government agencies, mDL issuers, app developers, OEMs | |
| Sigil NFC Hardware Module | A drop-in NFC hardware module engineered specifically for mDL transactions — solves the antenna, secure element, and protocol challenges so device makers don’t have to | Device manufacturers, terminal builders, integrators |
| Sigil mDL Verifier | A complete, ready-to-use verifier device combining the module, software, and a verifier UI | Law enforcement, TSA, age-restricted retailers, financial institutions, healthcare providers |
You can license the software, buy the module, buy the finished verifier, or any combination. The pieces are designed to work together but don’t require each other.
How It Works in Practice
A typical mDL verification takes about 2 seconds. Here’s what happens during those seconds:
- The user opens their wallet app on their phone, where their mDL is stored
- They tap the phone to a Sigil verifier (or hold it nearby)
- The verifier requests specific information — only what’s needed, nothing more (e.g., “is this person over 21?” rather than the full date of birth)
- The user approves the request on their phone
- The phone transmits a cryptographically signed response over NFC
- The verifier validates the signature against the issuer’s public key, confirming the credential is real and unmodified
- The result is shown — verified or not — and the transaction ends
Key properties of this flow:
- Selective disclosure — the verifier only sees what it needs (age, name, photo, license class — never the whole record unless required)
- Offline-capable — neither phone nor verifier needs an internet connection at the moment of verification; cryptographic signatures prove authenticity without a live database lookup
- Tamper-evident — any modification to the credential breaks the signature
- Privacy-preserving — no central server logs any Personally Identifiable Information (PII)
Standards & Compliance
Sigil is built to ISO/IEC 18013-5, the international standard for mobile Driver’s Licenses, and is designed to support ISO/IEC 18013-7 (online presentation).
Our products are engineered with these compliance pathways in mind:
- ISO/IEC 18013-5 — mDL device retrieval (NFC and BLE transport)
- ISO/IEC 18013-7 — mDL online retrieval (in development by ISO)
- AAMVA mDL Implementation Guidelines — North American DMV interoperability
- FCC Part 15 / CE RED — wireless hardware certification
- NIST SP 800-63-3 — identity assurance levels (where applicable to issuer integrations)
For verifier hardware: also designed to integrate with EMVCo payment infrastructure where the same device is used for both ID verification and contactless payment (a growing pattern in retail).
The Technical Layer
This section is for engineers and integrators evaluating Sigil for technical fit.
Architecture Overview
Sigil’s architecture follows the ISO 18013-5 model: an mDL holder (the phone) and an mDL reader (the verifier) exchange data over a defined transport using a defined data model and security envelope.
Holder side (phone):
- mDL credential stored in a secure container (Android StrongBox, iOS Secure Enclave, or equivalent)
- Third parties provide credential issuance, storage, presentation logic, and selective disclosure
- Engagement: NFC (ISO 14443 / ISO 18092) for tap; QR code displayed by phone for phones that don’t have NFC
- Transport: NFC (ISO 14443 / ISO 18092) for in-person verification; BLE (Bluetooth Low Energy) as an alternative transport
- Cryptographic operations: ECDSA signatures (P-256, P-384), session encryption per ISO 18013-5 Annex D
Verifier side (reader):
- Sigil verifier software validates signed mDL responses against issuer-published trust anchors (IACA certificates)
- Sigil NFC hardware module handles the RF layer, ISO 14443 / 18092 protocol, and APDU framing
- Verifier UI presents results, logs verification* (where required), and integrates with downstream business systems via REST APIs
*No PII is ever logged
Sigil NFC Hardware Module
The hardware module is a self-contained NFC subsystem solving the parts of mDL verification that are difficult to get right:
| Component | Purpose |
|---|---|
| NFC controller | Built around a production-proven NFC frontend with NXP NfcRdLib firmware support |
| Antenna* | Tuned for mDL phone form factors and typical user-device alignment |
| Secure element | Optional, for verifier-side key storage and certified cryptographic operations |
| Microcontroller | Hosts firmware, provides host-interface (UART, SPI, USB, or I2C) |
| Tamper detection | PCI-grade tamper protection for the EMV-payment-capable variant |
The module is offered as a drop-in component for device makers and as a reference design licensed to OEMs who need to manufacture at volume.
* The antenna is designed and customized per implementation due to the tight connection between the mechanics of the enclosure and the antenna performance. This is a one time NRE fee.
Sigil mDL Software & SDK
The SDK is delivered as native libraries for the supported platforms:
- Android (Java) — minimum SDK supporting StrongBox-backed key storage
- iOS (Swift) — Secure Enclave integration, supports Apple’s mobile credential frameworks <– keep but hide, for future release
- Verifier-side — C/C++ core library with bindings for embedded targets (verifier hardware) and server-side language bindings (for back-office integrations)
The SDK exposes APIs for:
- Verification (verifier side) — validating signatures, checking revocation status, presenting results
Integration Points
For organizations integrating Sigil:
- Verifier integration for in-person verification (retailer, agency, OEM): SDK for embedded and Android / Windows / Linux devices for in-person verifiers
- Verifier integration for online verification (forms, online ID verification): REST API
- Audit and Logging REST API for back-office verification logging and analytics
Security Architecture
- All credential material protected by hardware-backed key storage
- Session keys established per-transaction via ECDH; never reused
- Issuer signatures verified against IACA trust anchors with optional certificate transparency
- For verifier hardware: tamper detection, secure boot, encrypted firmware updates
- No credential data persisted on the verifier beyond the active transaction (configurable per deployment)
Why Sigil
What differentiates Sigil from a generic ISO 18013-5 implementation:
- Antenna-to-app expertise — we own the entire stack (RF, hardware, firmware, software, integrations). Most mDL vendors are software-only or hardware-only and force integrators to bridge the gap.
- NFC specialization — Sigil and Ingenutec have been engineering NFC since 2009. mDL is built on NFC. This isn’t a software company learning hardware.
- Production-grade hardware module — drop-in module solves the difficult RF and antenna engineering that derails most in-house attempts.
- EMV-compatible variant — for retailers and terminals that need to verify ID and accept contactless payment in the same device, our module supports both.
- Direct engineering access — clients work with the engineers building the product, not account managers.
What’s Next
Want to evaluate Sigil for your use case?
- For licensing or integration discussions: contact info@sigilidentity.com
- For developer evaluation of the SDK: request access via [demo request form] —> there will also end up being a live online demo for online verification.
- For verifier hardware purchase: contact sales@sigilidentity.com —> there will also, likely be a store.
Last updated: April 27, 2026
