JavaCard/NFC Smartcard Signer

Display-less APDU custody. The card cannot provide trusted event review by itself; external review acknowledgement is required before any APDU signing operation reaches the card.

Current evidence

  • Python APDU codec with GET_PUBLIC_KEY and SIGN_EVENT_ID proprietary constants.
  • secp256k1-backed simulator returning x-only public keys and signatures on 32-byte event ids.
  • nsealr-smartcard CLI probes for simulator and PC/SC probes; PC/SC commands fail clearly without pyscard or a reader.
  • Tests against shared nSealr/specs event-id and APDU status-word rejection vectors.
  • no trusted review or real-card compatibility claim yet.
Feature Target Current Contract
request_validation_v0 required partial signing-request-v0+implementation-limits-v0+invalid-vectors
approval_digest_binding required partial approval-digest-v0
sign_event_bip340 required partial nostr-sign-event-bip340-v0
persistent_secret_custody required partial persistent-secret-custody-v0
smartcard_apdu required implemented smartcard-apdu-v0
external_review_acknowledgement required partial external-review-acknowledgement-v0
response_verification required partial signed-response-verification-v0
device_display_review not_applicable not_applicable
physical_approval not_applicable not_applicable
stateless_session_custody forbidden forbidden

Repository

github.com/nSealr/smartcard