ARCTIC Conference 2026 Workshop: Pseudo ID Verifier

A hands-on iOS workshop for building a simulated ISO 18013-5 compliant mobile ID verification system.

Overview

In this workshop, participants will build PseudoIDVerifier, an iOS app that demonstrates the core concepts of mobile identity verification using two iPhones:

• Reader Phone (Verifier): Initiates verification sessions and receives identity data
• Presentment Phone (Holder): Presents credentials with selective disclosure and biometric approval

The Ideal Flow: NFC Tap → BLE Data Transfer

ISO 18013-5 and Apple's ID Verifier API define the following flow:

         Reader Phone                              Presentment Phone
          (Verifier)                                   (Holder)
    ┌──────────────────┐                        ┌──────────────────┐
    │                  │                        │                  │
[1] │  "Tap to Verify" │       NFC TAP          │  NFC Tag Ready   │
    │  NFC Session     │◄══════════════════════►│  (HCE)           │
    │                  │    DeviceEngagement     │                  │
    │                  │    (CBOR + BLE UUID)    │                  │
    ├──────────────────┤                        ├──────────────────┤
    │                  │                        │                  │
[2] │  BLE Connect     │◄═══ BLE Connection ═══►│  BLE Peripheral  │
    │  (Central)       │    using UUID from NFC  │                  │
    │                  │                        │                  │
[3] │  Send Request    │═══ DeviceRequest ═════►│  Show Request    │
    │  (CBOR)          │                        │  (Disclosure UI) │
    │                  │                        │                  │
[4] │                  │                        │  Face ID Auth     │
    │                  │                        │  Touch ID Auth    │
    │                  │                        │                  │
[5] │  Receive         │◄══ DeviceResponse ════│  Send Response   │
    │  (CBOR + mdoc)   │                        │  (filtered mdoc) │
    │                  │                        │                  │
[6] │  CBOR Decode     │                        │                  │
    │  Display Key-Values   │                        │                  │
    └──────────────────┘                        └──────────────────┘

iOS Technical Constraints: Why NFC Tap Cannot Be Reproduced

Step [1] NFC TAP in the flow above cannot be implemented in third-party apps:

Feature	Status on iOS	This Workshop
NFC Tag Reading (Reader)	Possible with NFCNDEFReaderSession	Reference implementation provided
NFC Tag Emulation (Holder)	HCE available since iOS 18.2 via NFC & SE Platform, but requires entitlement request to Apple; unclear if general developers can obtain approval	Substituted with direct BLE connection
CardSession (iOS 17.4+)	EEA only / payment use only	Out of scope
Apple ID Verifier API	ProximityReader framework / dedicated entitlement required	Concepts explained

Why Apple's ID Verifier API works:

1. Reader side: ProximityReader performs NFC polling via Enhanced Contactless Polling (ECP)
2. Holder side: Apple Wallet returns DeviceEngagement as an NDEF tag at the system level
3. Both are Apple's proprietary implementation -- cannot be reproduced by third parties

Actual Flow in This Workshop

Instead of NFC tag emulation, we use direct BLE connection:

         Reader Phone                              Presentment Phone
          (Verifier)                                   (Holder)
    ┌──────────────────┐                        ┌──────────────────┐
    │                  │                        │                  │
[1] │  "Tap to Verify" │                        │ "Present ID"     │
    │  BLE Scanning    │                        │  BLE Advertising │
    │                  │                        │                  │
[2] │  BLE Connect     │◄═══ BLE Connection ═══►│  BLE Peripheral  │
    │  (Central)       │                        │                  │
    │                  │                        │                  │
[3] │  Send Request    │═══ DeviceRequest ═════►│  Show Request    │
    │  (CBOR)          │                        │  (Disclosure UI) │
    │                  │                        │                  │
[4] │                  │                        │  Face ID Auth     │
    │                  │                        │                  │
[5] │  Receive         │◄══ DeviceResponse ════│  Send Response   │
    │  (CBOR + mdoc)   │                        │  (filtered mdoc) │
    │                  │                        │                  │
[6] │  CBOR Decode     │                        │                  │
    │  Display Key-Values   │                        │                  │
    └──────────────────┘                        └──────────────────┘

All steps other than NFC tag emulation (BLE connection, CBOR encoding/decoding, selective attribute disclosure, biometric authentication) are implemented in compliance with ISO 18013-5.

Project Structure

arctic-workshop-2026/
├── initial/                    # Starter project with TODOs
│   └── PseudoIDVerifier/
│       └── PseudoIDVerifier/
│           ├── Models/         # Data structures
│           ├── Services/       # Core functionality (TODOs here)
│           └── Views/          # SwiftUI views
├── completed/                  # Reference implementation
│   └── PseudoIDVerifier/
│       └── PseudoIDVerifier/
│           ├── Models/
│           ├── Services/       # Fully implemented
│           └── Views/
└── Documentation.docc/         # Step-by-step tutorials

Getting Started

Prerequisites

• Xcode 15.0 or later
• Two iPhones running iOS 17.0+
• Apple Developer account (for device testing)

Setup

1. Clone this repository
2. Open initial/PseudoIDVerifier/PseudoIDVerifier.xcodeproj in Xcode
3. Update the bundle identifier and signing team
4. Build and run on two devices

Workshop Flow

1. Understanding mDL - Learn ISO 18013-5 data structures
2. CBOR Encoding - Implement binary serialization
3. NFC Handshake - Understand device engagement (includes learning iOS constraints)
4. BLE Transport - Build the communication layer
5. Selective Disclosure - Implement privacy-preserving data sharing
6. Biometric Authentication - Add Face ID/Touch ID approval
7. Integration Testing - Test the complete flow

Documentation

Open the DocC documentation in Xcode:

cd Documentation.docc
open ../initial/PseudoIDVerifier/PseudoIDVerifier.xcodeproj
# Product > Build Documentation

Or read the markdown files directly in Documentation.docc/.

Key Concepts

ISO 18013-5

This workshop simulates the ISO 18013-5 standard for mobile driving licenses (mDL):

• mdoc: Mobile document containing identity attributes
• IssuerSigned: Attributes signed by the credential issuer
• DeviceSigned: Proof that the device holds the credential
• Selective Disclosure: Share only requested attributes
• DeviceEngagement: Connection establishment data (CBOR-encoded)

Architecture

Component	Description
MDoc	Mobile document data structure
CBORService	CBOR encoding/decoding
BLEService	Bluetooth communication (Central & Peripheral)
NFCService	NFC handover (Reader-side reference implementation / iOS HCE constraint)
AuthenticationService	Biometric approval (Face ID / Touch ID)
CryptoService	ECDSA signing, ECDH key agreement

Communication Flow

1. Reader starts BLE scanning (Tap to Pay style UI)
2. Holder starts BLE advertising
3. Devices connect over BLE
4. Reader sends DeviceRequest (CBOR)
5. Holder shows selective disclosure request to user
6. User approves with Face ID / Touch ID
7. Holder sends DeviceResponse with filtered mdoc (CBOR)
8. Reader decodes CBOR and displays verified key-value attributes

iOS Technical Constraints

This workshop teaches what is and isn't possible on iOS for NFC-BLE identity verification:

What This Workshop Implements (Fully Functional)

• BLE Central/Peripheral communication
• CBOR encoding/decoding per ISO 18013-5
• mdoc data structures (IssuerSigned, DeviceSigned)
• Selective disclosure filtering
• Face ID / Touch ID biometric approval
• DeviceRequest / DeviceResponse protocol

What iOS Cannot Do (Explained in Documentation)

• NFC Tag Emulation (HCE) — Available since iOS 18.2 but requires entitlement request; general developer availability uncertain
• ProximityReader without entitlement — requires Apple contract
• Cross-app NFC tag emulation — no public API exists

Related Apple Technologies (Explained in Documentation)

• Apple ID Verifier API (ProximityReader framework)
• Enhanced Contactless Polling (ECP)
• NFC & SE Platform (iOS 18.2+ for HCE, requires entitlement request)
• CardSession (iOS 17.4+, EEA only)

Files to Complete

In the initial/ project, look for fatalError("TODO:") comments:

• Services/CBORService.swift - CBOR encoding/decoding
• Services/BLEService.swift - BLE communication
• Services/NFCService.swift - NFC handover (Reader-side reference implementation)
• Services/AuthenticationService.swift - Biometric auth

Resources

• ISO 18013-5 Standard
• Apple CoreBluetooth
• Apple CoreNFC
• Apple ProximityReader (ID Verifier)
• Apple LocalAuthentication
• SwiftCBOR Library

License

MIT License - See LICENSE file for details.

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ARCTIC Conference 2026 - Building the Future of Digital Identity