Servers implementing the eXtensible Messag-ing and Presence Protocol (XMPP) enable the near-real-time exchange of structured yet extensible data between any two or more network entities. In this paper we propose to address network attacks, a security issue, by implementing signing forms over an in-band registration mechanism. We validate our proposal implementing this mechanism over OpenFire, which is a free, community-supported and open source XMPP server. Our experiments showed that the number of successful attacks was reduced to 0 when our proposal is implemented.