World‑readable .aux and .log files after TeX compilation

After a TeX run with the default settings, the auxiliary files .aux and .log are created with the process’s umask. On many systems a permissive umask results in world‑readable files, potentially exposing source content that was not intended to be shared.

The goal is to decide whether TeX should alter its file‑creation routine to enforce more restrictive permissions for these files, independent of the invoking umask, in order to reduce the chance of accidental disclosure.

This change must be weighed against existing workflows that rely on group or world readability (e.g., shared build directories, log‑processing scripts) and against the principle of honoring the user’s umask. The effect may differ between pdftex, XeTeX, LuaTeX and across TeX Live releases.

Should TeX internally set a more restrictive mode (e.g., 0600) for .aux and .log files when the umask allows broader access? Would an explicit option to control auxiliary‑file permissions be preferable to changing the default? How would a stricter default impact documents built in shared or automated environments?