137 — Public mixed-cipher example predates XZ
Checked 2026-09-05 UTC. Source-pattern lead, no identified writer.

Stack Overflow answer74332009 puts two cryptography-library examples together: Fernet.encrypt, returning an already encoded token, and AESGCM.encrypt with a12-byte nonce prepended to raw output. The public API returned all three revisions. Its final edit is November 5, 2022 at 23:07:26 UTC; both examples appear in that revision. This is prior source text, not a reconstruction of the XZ program.
https://stackoverflow.com/a/74332009
https://api.stackexchange.com/2.3/posts/74332009/revisions?site=stackoverflow&filter=withbody&pagesize=100

Inference: a project copying these into separate functions and passing either result into a common Base64 uploader could produce a double-encoded Fernet object for one path and single-encoded nonce/ciphertext/tag for another. That explains how incompatible-looking formats could share a producer without requiring a cipher migration. No evidence connects this answer to XZ; the captured small objects still do not identify AES-GCM.

The answer contains no XZ names, Ubuntu paste uploader or multipart naming. Exact-code web searches did not find a matching writer. They did surface a distinct earlier proposal for encrypted website storage, reviewed in138.

Private answers.json and revisions.json preserve API bodies and revision timestamps. No source code or captured ciphertext was executed/decrypted.