This extension lets any new IP do a proof-of-work test first. The proof-of-work works as such:

- The server generates a nonce N (time and ip dependent)
- The server generates a random number R
- The server has a secret key K
- The server calculates C=md5(N.R)
- The server calculates H=md5(C.K)
- The server sends N, C and H to the client
- The client brute-forces r until C==md5(N.r)
- The client sends back N, r, H
- Server checks if N matches requested IP, timestamp; server checks if C==md5(N.r); server checks
  if H=md5(C, K)

If the response is correct, the IP will be allowed to access the forum for a week.