Skip to content

SPEC_REFERENCE.md

Latest commit

 

History

History
77 lines (52 loc) · 2.08 KB

SPEC_REFERENCE.md

File metadata and controls

77 lines (52 loc) · 2.08 KB

📜 Spec v1.2/v1.3.1 Reference Implementation

The spec-aligned implementation lives under meow_decoder/spec_v12 and provides a complete reference for the protocol specification.

Features

  • Unified Ed25519 identity keys (RFC 8410 conversion to X25519 for ECDH)
  • Sign‑header‑then‑encrypt‑payload with AAD binding
  • Dynamic GIF insertion/extraction (MEOW‑PAYLOAD)
  • Constant‑order multi‑tier processing

v1.2 Improvements Summary

Improvement Description
Stateless design Removed file_id
Enhanced AAD Includes signature field (prevents stripping)
Early detection Recipient public key in header
Flexible embedding Dynamic GIF insertion (no fixed offset)
Side-channel resistant Constant‑time multi‑tier handling

Usage Example

Single-Tier Encode/Decode

from meow_decoder.spec_v12 import SoftwareBackend, encode_file, decode_file

# Generate keys
sender = SoftwareBackend()
recipient = SoftwareBackend()
sender_sk, sender_pk = sender.generate_ed25519_keypair()
recipient_sk, recipient_pk = recipient.generate_ed25519_keypair()

# Encode
gif_carrier = open("carrier.gif", "rb").read()
encrypted_gif = encode_file(b"secret", recipient_pk, sender_sk, gif_carrier)

# Decode
plaintext = decode_file(encrypted_gif, sender_pk, recipient_sk)

Dependencies

Package Purpose
PyNaCl Required for Ed25519↔X25519 conversion
cryptography Core crypto primitives

Security Notes

Requirement Rationale
Uniform error messages All decryption failures must return "Decryption failed"
Constant-order processing Multi‑tier decode must process all tiers in constant order

Related Documentation

See the main README.md for quick start and installation.