BRY-NFET-SX is a controlled-use product preview. This page describes the current security posture, the hardening work completed, the trust model, and the limitations that remain open.
All packet encryption uses ChaCha20-Poly1305 AEAD provided by the Python cryptography library. Key derivation uses HMAC-SHA256. No novel cryptographic algorithms are introduced.
Cryptographic operations are delegated to the pyca/cryptography library, which wraps OpenSSL and Rust-based implementations. BRY-NFET-SX does not implement its own cipher.
Packet headers are bound as additional authenticated data. Header tampering, ciphertext modification, and field injection all cause authentication failure and are rejected.
| Field | Meaning |
|---|---|
| integrity_ok | SHA-256 manifest hashes match the actual file contents |
| signature_verified | HMAC-SHA256 digest is cryptographically valid |
| metadata_consistent | Key fingerprint derived from actual key material matches between signer and verifier |
| overall_trusted | True only when integrity, signature, and metadata consistency all pass |
Unsigned bundles, unchecked signatures, and failed verifications are never reported as trusted. The verification output distinguishes every state explicitly.
The system assumes a trusted local execution environment. It is not hardened for hostile multi-tenant deployment or untrusted API exposure.
Key material is managed locally via inline, environment variable, or file providers. There is no integration with managed key management services or hardware security modules.
There is no key rotation or revocation mechanism. Key versioning is supported as metadata but lifecycle operations are not automated.
The nonce registry uses fcntl file locking. This is not portable to Windows and is not suitable for network filesystems such as NFS.
Index rows are HMAC-bound to an auto-generated local secret (Phase 38C), so rows cannot be forged without reading the secret store. The index file as a whole is not independently signed, and an attacker who can read both the data directory and the secret store could still introduce forged entries.
The internal adversarial review identified and resolved critical issues. A formal third-party security audit has not been conducted.
For security-specific inquiries, include "Security Review" in the subject line.
Qira LLC is separately developing a candidate cryptographic primitive called NFET-SC-512 and an AEAD construction called BRY-NFET-AEAD-512. It is a research artifact, not part of this product. It has not been reviewed by any credentialed cryptographer and is not integrated into BRY-NFET-SX. The product above continues to use ChaCha20-Poly1305 exclusively for secrecy.
The spec, reference implementation, 18 pinned test vectors, and a first-pass self-attack report are published for external evaluation at github.com/TheArtOfSound/nfet-primitive. If you are a cryptographer willing to review or attack it, please do — credible findings will be acknowledged publicly.