141 — GetPost and Umbra container headers compared with XZ
Checked 2026-09-05 UTC. Concrete container exclusions; cipher still unidentified.

Primary source: https://github.com/getpost-loves-you/GetPost
GitHub metadata: created March1,2021; last push July7,2026. Captured tree34f682db4f92fa4aced64c47c70fb8179f7711e5. The encrypted CLI source was fetched by blob ID and independently Git-hash verified. The deps entry is a22-byte relative-path reference, not a second implementation. Captures/hashes:141-private/sources.json.

The inspected encryption function derives a key using Argon2id, calls NaCl SecretBox, and emits marker00 47 50 45 31 (NUL GPE1),16-byte salt, nonce and authenticated ciphertext. Its uploader submits binary data to /post. This differs from the large XZ objects' nested Fernet representation; no matching Ubuntu multipart writer was recovered.

New direct data check: all3495 small knowledge/plan bodies were reconciled against the frozen checkpoint SHA256 values, then decoded using the established space-to-plus/Base64 convention. None begins with the GetPost marker. None begins with Umbra's manifest magic plus little-endian version1:86 90 99 8b 01 00 00 00.

Thus none of these small records is an unmodified GetPost encrypted container or Umbra v1 manifest under this decoding. Custom extracted ciphertext, additional encryption/wrappers or modified implementations remain outside the exclusion. No algorithm, key, plaintext or operator has been identified.

Reproducible check:141-private/check_headers.py; results:header-check.json. No cipher operation, key guesses, source execution, submissions or excluded-page access. Archive hash remained unchanged.