The security of the information is an element of vital importance for the accompaniment of the vertical growth of the transactions saw Internet and of the use of computer networks, therefore today, is almost impossible them great corporations to keep the efficient communication between branch offices, customers and suppliers, without the aid of the Internet or of its private nets. The computer networks, in the same way that it becomes possible all this communication, with the transit and the storage of information in on computers the nets leave these same vulnerable information, as much accidental errors 12 of neglected users, how much the attacks right-handers of people moved for me the faith, or simply interested in invading other people’s systems and bisbilhotar private archives. Thus, the security of the information consists of excused protection ace information filed in computers against relative not authorized actions its spreading, transference, modification or intentional or accidental destruction. The security of the Information is not only one service or one politics, is an imperative and indispensable resource, that must be tax, projected good and to all follow the education of the body of professionals that makes use of YOU (Technology of the Information). when we deal with security in nets without wire the attention must fold, therefore, the data are transmitted by air through radio waves being able to be intercepted by another person easily, for this we must consequentemente implant tools and procedures of security that can diminish existing vulnerabilities in the nets without wire, diminishing its risks. This work is divided in four chapters, the first chapter is introduced describing the computer networks in a general way, then, they enter in the context of nets without wire 802.11x detailing of one forms specific its standards, format of picture and methods of transmission. Still in the first chapter some concepts of mechanisms of security are presented applied the nets without wire as, protocols WEP (Wired Equivalent Privacy) and WPA (Wi-Fi Protected Access). .