Shannon entropy check rejects low-entropy content when MIN_ENTROPY > 0. Encrypted data ~7.5-8.0 bits/byte, plaintext ~4.0-5.0 bits/byte. Configurable via FLASKPASTE_MIN_ENTROPY environment variable.
Throttle repeated submissions of identical content using SHA256 hash tracking. Configurable via FLASKPASTE_DEDUP_WINDOW and FLASKPASTE_DEDUP_MAX.