fast

The fast algorithm uses an optimized JavaScript implementation with multiple threads. The browser solves a proof of work puzzle before it receives a token for the protected service.

Difficulty counts the leading hexadecimal digits that the solution must match. Each hexadecimal digit represents four bits.

Configuration

Use fast in a threshold rule:

thresholds:
  - name: moderate-suspicion
    expression:
      all:
        - weight >= 10
        - weight < 20
    action: CHALLENGE
    challenge:
      algorithm: fast
      difficulty: 2

See thresholds for rules based on request weight.