Document Verification & NFC e-Chip Reading (eMRTD / ICAO 9303)
How modern ID documents are verified using optical checks, NFC chip reading, and PKI validation per ICAO Doc 9303.
Overview
Modern passports and many IDs are electronic Machine-Readable Travel Documents (eMRTDs) with an NFC chip. Verifying them combines visual checks with chip reading and PKI cryptographic validation to confirm authenticity and detect tampering.
How it works
- Optical checks: MRZ, VIZ, security features.
- Secure messaging: Use MRZ or CAN to start BAC/PACE.
- Chip read: Extract LDS data groups (e.g., DG2 face, DG1 MRZ) and SOD.
- PKI validation: Verify SOD signature using issuer’s DSC/CSCA; trust roots often fetched via the ICAO PKD.
- Consistency checks: Compare chip data vs printed data; run face match to selfie if needed.
Common use cases
- Border control; eGate flows
- Remote KYC / onboarding (NFC on smartphones)
- Airport or workplace issuance/verification
Strengths and limitations
Strengths: Cryptographic authenticity, global standards, offline verification with cached trust lists.
Limitations: Access to trust anchors; device NFC variability; privacy rules on biometric access.
Key terms
- LDS (Logical Data Structure): Standardized layout of chip data (DG1..DG16 + SOD).
- PKD: Global repository of signing keys and revocation material.