Security Policy

Fine-tune how SilentShield protects your forms with IP filters, rate limits, and challenge modes.

In your dashboard, go to API Keys → select a key → Security tab.

Security Options

OptionDescription
IP WhitelistOnly allow requests from these IPs or CIDR ranges (e.g., 192.168.1.0/24)
IP BlacklistBlock requests from these IPs or CIDR ranges
Country BlockBlock requests from specific countries by ISO code (e.g., CN, RU)
Bot ThresholdScore below this value is considered a bot (default: 0.3, range: 0.0–1.0)
Challenge ModeDecides WHETHER to ask: 'always', 'suspicious' = only on suspicious behaviour (default), 'never' = never ask. What happens to the submission is set by the three actions below — 'never' on its own is not monitor-only. (action_suspicious, action_bot, action_unverified)
action_suspiciousWhat happens on verdict 'suspicious': 'challenge' (default), 'block' or 'allow'.
action_botWhat happens on verdict 'bot': 'challenge' (default), 'block' or 'allow'.
action_unverifiedWhat happens when a nonce has no telemetry: 'block' (default) or 'allow'. No 'challenge' — the visitor is long gone, there is nobody left to ask.
action_torWhat happens to a submission arriving over a Tor exit node: '' (default, record only), 'report', 'challenge' or 'block'. Empty means nothing changes.
Rate Limit per IPMaximum requests per IP per minute (default: 100)
Allowed ReferersAdditional domains allowed to send requests

Escalation Levels

SilentShield uses a 5-level escalation system based on the behavior score:

Score RangeLevelAction
0.85 – 1.0PassNo challenge — user is clearly human
0.7 – 0.85EasyInvisible proof of work, 18 bits (~260,000 hashes) — half a second to a few seconds depending on the device
0.5 – 0.7MediumProof of work, 20 bits (~1 million hashes)
0.3 – 0.5HardProof of work, 22 bits (~4.2 million hashes) + visible arithmetic captcha as fallback
0.0 – 0.3BlockRequest is rejected (HTTP 403)