• Attackers may attempt active network interception, replay, or message tampering on untrusted networks.
• Malicious peers could try to exhaust resources via oversized frames, rapid reconnects, or crafted handshake data.
• Offline adversaries may capture encrypted traffic and attempt password guessing or key derivation attacks.
• Compromised endpoints are out of scope; the focus is on securing transport and key derivation between honest nodes.

• Password-based encryption now relies on Scrypt with parameters N=2**15, r=8, p=1, and length=32 bytes.
• Each encrypted payload stores a 16-byte random salt and 12-byte nonce before the ciphertext. These values must be supplied on decryption to recompute the AES-256-GCM key stream.
• Ephemeral session keys from X25519 handshakes are mixed with the Scrypt-derived PSK via HKDF (SHA-256, info "neccrit session") to ensure forward secrecy even if long-term secrets leak.

• Nodes perform an ephemeral X25519 Diffie-Hellman exchange per connection. The shared secret is strengthened with HKDF and the deterministic PSK derived from the shared password.
• QR codes generated by qr_utils.py should distribute only public information (peer display name and base64-encoded public key). Never embed passwords or private keys in QR payloads.
• Users should verify public-key fingerprints out-of-band before trusting new peers (Trust-on-first-use is discouraged for high-risk environments).

• Messages include a 32-hex-character msg_id and a Unix timestamp. Receivers maintain a bounded, TTL-protected LRU cache (300s / 10k entries) per peer to block replays and stale traffic.
• Frame sizes are capped at 256 KiB, sockets enforce 10s timeouts, and connection attempts are rate-limited (20 per 30s per IP) to mitigate resource exhaustion.

• Open a private report via GitHub Security Advisories for this project.
• We aim to acknowledge reports within 3 business days and provide status updates every 7 days until resolution.

• Security updates currently target the main branch; legacy releases are unsupported. Consumers should track the changelog for hardening updates.

The repository contains optional add-ons under addons/ that provide cover-traffic and steganography features intended for research and defensive privacy studies. These modules are disabled by default.

Operational rules:

• Official core releases (artifact neccrit-core-*.tar.gz) exclude addons/.
• To enable add-ons locally, use python tools/enable_addons.py and follow the confirmation prompt.
• Steganography (ENABLE_ZW_STEGANO) requires a second explicit confirmation (tools/enable_stegano.py).
• Each enabling action is logged locally in data/audit.log.
• For distribution to third parties or enterprise use, prefer neccrit-core artifact or remove addons/ entirely.

If you are unsure about legal implications in your jurisdiction, consult legal counsel.