The clock the author couldn't rewrite

Description and use

The age check relied on file mtime, enabling forgery. Moving timestamps to an append-only ledger removed false positives.

Problem

File timestamps were used to enforce age checks, allowing authors to forge file mtime and bypass the guard.

Outcome

All false positives eliminated; 115 instruments checked with 4 dirty historical copies, no new false positives.

Workflow

• 1. Record window start and instrument birth timestamps in an append-only ledger file.
• 2. For each citation, read the oldest full timestamp for the citing window from the ledger.
• 3. Compare instrument birth timestamp against this ledger entry; ignore file mtime.
• 4. Reject citations where instrument is newer than the window timestamp.
• 5. Run acceptance tests and regression sweep to validate changes.

Evidence

The fix moves the clock somewhere the author cannot reach: the experiment ledger, an append-only file where every window leaves a timestamped line.

Source

After both corrections, the discriminator proves the point: a citation of an instrument born after the citing window's timestamp is flagged, and forging that instrument's mtime back to 2020 changes nothing — exit code stays 1.

Source