This project was built to be safe with no vulnerabilities and no privacy leaks. Summary of the audited posture:

• Offline by default. The core app makes no network calls — no telemetry, no update checks, nothing uploaded. The bundled amiibo_db.json is read locally.
• Opt-in online features (two, both download-only):
  • "Show image" (n2elite/amiibo/images.py) fetches an amiibo's public figure icon from a fixed host (AmiiboAPI on GitHub) only when you explicitly ask, then caches it locally so it never re-fetches.
  • "Download offline data" / n2elite sync (n2elite/amiibo/sync.py) optionally downloads the full amiibo database and pre-caches every figure image, so the app then runs with no network at all. Bounded concurrency; already-cached files are skipped. Both send only GETs for public data keyed by amiibo ID — no personal data, no dumps, no keys. Both use HTTPS with certificate validation, fixed public hosts, a short timeout, per-response size caps (2 MB per image, 16 MB for the database), and content validation (PNG-magic for images, JSON parse for the database) before anything is written (atomically). Nothing else in the app ever touches the network.
• Your keys stay yours. key_retail.bin is only ever read, used for in-memory key derivation, and never printed, logged, transmitted, or written back. It is git-ignored, as are *.bin, dumps/, backups/, and captured serial logs.

• No eval, exec, __import__, pickle/marshal (no untrusted deserialization), no subprocess, os.system, os.popen, or shell=True.
• All external input is length-validated before use: amiibo dumps must be 540/572 bytes; key files must be 160 bytes; MFRC522/NTAG responses are bounded and checked.
• Serial I/O uses timeouts and bounded retries — no unbounded blocking or hangs.

• Reads are non-destructive. Writes are gated: a valid size is required, the GUI confirms before writing, and the workflow is backup-first.
• No firmware flashing. The N2 firmware-update path exists in the reference tools but is deliberately NOT implemented — it carries a bricking risk (per user directive).

• Runtime dependencies: pyserial, pycryptodome (both mainstream, with minimum versions declared in pyproject.toml). Crypto uses pycryptodome (AES) + the standard library hmac/ hashlib — no hand-rolled primitives.
• Build tooling (PyInstaller, a portable Python for Wine) is used only at build time and is not part of the shipped app.

This is a personal-use interoperability tool. Report issues privately to the maintainer; do not include your key_retail.bin or any amiibo dumps in reports.