Summary
This release introduces the physical paper backup workflow. Users can now produce a compact, scan-friendly QR PDF that encodes a Lite Vault ZIP, providing an additional safeguard against file corruption or loss.
Paper Backup (Lite ZIP → QR PDF)
Generates a single PDF containing:
MVKEY: one-time file key (hex).
MVHDR: header (version, IV, size, SHA-256 of plaintext Lite ZIP).
MVCT: ciphertext tiles (base64, 1200 characters per tile).
Layout:
Three tiles per row, centered grid, rendered at ~300 DPI.
Four-module quiet zones around QR codes for reliable scanning.
Page banner includes build timestamp, version, ZIP byte size, and SHA-256 checksum.
EC(Q) for KEY/HEADER; EC(M) for CT tiles.
Lite picker modal:
Users select which seed files, uploads, and whether the final message is included.
Enforces a ~150 KiB cap on raw size for practical QR count.
Encryption and Integrity
Lite ZIP encrypted with AES-GCM using a random 32-byte key and IV.
Header contains plaintext SHA-256 for integrity verification when reconstructing from QR codes.
Guidance
The paper backup is an optional but recommended safeguard.
Best practice is to maintain both the full vault ZIP and the QR PDF, stored redundantly across M-DISC, offline media, and cloud.
Do not modify filenames or contents within the vault ZIP, as any change will break recovery.