Parece que você está mais ou menos ciente de que o ocultamento de SSID não torna sua rede sem fio mais segura .
O que a maioria das pessoas não sabe, porém, é que esconder seu SSID pode realmente expor mais informações do que deixá-lo visível, dependendo do sistema operacional do cliente. Ocultar seu SSID também torna sua conexão mais propensa a problemas de desempenho e estabilidade.
Meu artigo favorito sobre o assunto, apesar de um pouco datado: Blogs da Technet: SSIDs sem fio sem difusão Por que redes sem fio ocultas é uma má ideia .
Sobre o risco de vazar mais informações ao ocultar o SSID
The name of the network itself is only an identifier and is not a security element. In fact the name of the network has no bearing on security whatsoever from an encryption or authentication standpoint.
If the network name of a wireless network (SSID) is not broadcast, the clients must search for it with probe requests. So if you have one AP and 100 wireless devices, you partially limit exposure of the network name with one device while causing 100 devices to expose it instead. The probe frames sent by the clients advertise the SSID every 60 seconds, whether they are close to the actual AP or not. This means that instead of one device broadcasting the SSID in the immediate proximity of your network, you now have these 100 devices potentially advertising the SSID in every coffee shop, hotel, and airport they visit. The security vulnerability this exposes is worse the larger the wireless deployment is.
Mais tarde resumido:
Non-broadcast SSIDs are not a valid security measure and actually make it easier for the SSID to be discovered since it forces clients to continuously probe for it.
Em SSID ocultos sendo mais propensos a problemas de conexão
In order for the new process to work, the wireless driver must send the probe packet to the AP for the hidden SSID. We have seen that power settings defined on the NIC driver can influence whether the AP receives this probe. Sometimes setting the transmit power setting to maximum will allow the probes to reach the AP.
Currently there are several widely-distributed WLAN drivers which either do not support or do not work properly with the Vista method of dealing with non-broadcast SSIDs, including the Intel 3945ABG and the Broadcom 802.11g Network Adapters.
The Intel 3945ABG adapter is very widely distributed in current laptop models. The latest Intel driver provides improvement but does not address all issues with hidden SSIDs encountered when roaming or resuming from hibernation.
Broadcom does not show any unnamed networks, and they are not planning to fix this. One of the reasons, besides being low priority for them, is also to push customers to stop hiding the SSID, which creates a problem instead of solving it.
