Authorized NFC reading
The CAN helps establish a secure channel with the card. The data PIN authorizes access to available information. PINs are used only in the current session. If you choose, the CAN can be remembered in the device Keychain, protected by Face ID, Touch ID, or the passcode. Codes are not synced to iCloud.
eID data authentication
The app reads the security object EF.SOD, EF.COM, and the MRZ (DG1) and compares the data, photo, and handwritten signature with the hashes signed by the issuer. The issuer's signature is verified on the device against the CSCA Romania certificates bundled with the app, without internet access; no data leaves the device for this check. The reading result and identity reports state what is cryptographically verified and what is not covered by the issuer's signature, such as the address.
Signing on the card
The cryptographic operation is authorized with the signing PIN and executed with the private key inside the eID. The app receives the signing result, never the private key.
Timestamp and PAdES-LT
For newly signed documents, the app requests a trusted timestamp from DigiCert (GlobalSign and Sectigo only as fallbacks), sending only the signature hash, and archives the certificate chain and revocation lists (CRL) inside the PDF so long-term validation has the required information. Evidence for your certificate is downloaded before the signing operation on the card.
Local and online verification
Library documents are verified automatically on the device without internet, using the PDF's own data and the built-in trusted certificates. Online revocation and chain checks, at the addresses referenced by certificates, happen only when you ask: on the verification screen, when opening the signatures of a document without a saved result, or with "Verify again".
Library and iCloud
The library is local by default. If iCloud is enabled, eligible PDFs and their metadata are stored in your private CloudKit database; a signed PDF is synced in full. Access codes, identity reports, and proof-of-address documents are excluded.
What you can do
Keep iOS and macOS updated, use the correct codes, review every document before signing, protect access to your iPhone and Mac, and share PDFs only with the intended recipients.