# Privacy and security boundaries

- No calculator performs runtime network access, telemetry or persistence.
- No input is restored after refresh. The service worker caches only static app
  files, never calculator values.
- Binary/text allocation, structured nesting, row/column counts, random output
  and numeric digits have explicit ceilings.
- JSON dangerous object keys are rejected by default. CSV and URL values remain
  text; they are never evaluated or opened automatically.
- IP helpers calculate notation and CIDR membership without scanning, DNS or
  connectivity checks.
- SHA results are digests, not proof of authenticity. CRC, Adler and FNV are not
  cryptographic. Seeded random output is not secret.
- Download names remove path/control and bidirectional-override characters,
  avoid Windows device names and are truncated without splitting surrogate
  pairs. Object URLs are revoked. A user must still choose how and where
  downloaded text is used.