This is a module for MySQL Bot Core system.
You'll need http://www.hawkee.com/snippet/8882/ in case for this to work.

PHP Side: http://www.hawkee.com/scripts/20788797/

[14:59] -##SQL- To verify yourself and gain +v (ability to talk), please visit http://127.0.0.1/verify/

; MySQL Bot Core
; Module: Human Verification
; Version: 1.00 STABLE
; Author: Nils Putnins (Neisen@Neisen.lv)

; - aliases
alias -l m.hver.cfg {
  if ($1 == channel) return #yourchan
  else if ($1 == url) return http://url.to.php.script/
}
alias -l m.hver {
  if ($prop == sync) {
    var %chan = $m.hver.cfg(channel)
    if ($me isop %chan) || ($me ishop %chan) {
      if (m !isincs $chan(%chan).mode) mode %chan +m
      var %sql = SELECT * FROM `captcha`, %chan = $m.hver.cfg(channel)
      var %data = $mysql_query(%m.sql, %sql)
      while ($mysql_fetch_row(%data, captcha)) $iif($ial($+(*@,$hget(captcha, address))).nick,mode %chan +v $v1)
      mysql_free %data
    }    
    var %sql = DELETE FROM `captcha` WHERE `time` < (NOW() - INTERVAL 30 SECONDS)
    noop $mysql_query(%m.sql, %sql)
  }
  else if ($prop == key) return $m.dbres(address,captcha,key,$1)
}

; - actions
on *:JOIN:#:if ($chan == $m.hver.cfg(channel)) notice $nick To verify yourself and gain +v (ability to talk), please visit $bold($uline($m.hver.cfg(url)))
on *:TEXT:*:?:{
  if ($1-2 == verify me) && ($len($3) == 3) {
    if ($m.hver($3).key) {
      var %address = $v1
      $iif($me isop $m.hver.cfg(channel),mode $v2 +v $nick)
      var %sql = DELETE FROM `captcha` WHERE `address` = ?
      noop $mysql_query(%m.sql, %sql, %address)
      msg $nick Thank you, you're now verified.
    }
    else msg $nick Sorry, I don't recognize such key. Maybe it's expired?
  }
}

; - communicating with core
on *:SIGNAL:m.modules:{
  m.modules $+(Human Verification,$chr(124),$chr(124),0)
  noop $m.hver().sync
}