What is SSID?

When looking to join a wireless network from your smartphone, laptop, or tablet, users are typically presented with a list of names to click on. These names are known as a service set identifiers (SSIDs), which can either be the default labels given to the network by the manufacturer or a customised name created by the owner.

Default SSIDs normally follow a distinct pattern unique to the manufacturer. For example, Virgin Media begins its SSIDs with the prefix VM followed by a set of numbers, such as VM-12345. Sky and BT follow a similar pattern. A number of manufacturers also do this with devices they sell to the consumer, such as Netgear.

You may wish to change the SSID from a set of letters and numbers into something more memorable and to distinguish it from similar routers in the neighbourhood. This can be done by accessing the web-based admin settings found in nearly all modern routers.

This is also the case if you have many networks in one building – for example, guest Wi-Fi and employee Wi-Fi – that you want to keep separate. Just change the names to make it clear who should use which network.

Key features of an SSID

One common theme you’ll find with an SSID, whether it’s the default set by the ISP or router manufacturer or you’ve changed it, is it features up to 32 case-sensitive letters and numbers. Although you can use up to 32 characters, there’s no lower limit, but it’s recommended you don’t make the SSID so short that it causes confusion (for example “me” or a couple of digits).

SSIDs are normally provided as part of the set-up materials and printed on a sticker attached to the outside of the router, which also includes the password. Alongside the SSID and password should also be the username and password for the router’s administrator console, which grants access to network data and options for configuring settings, including the SSID.

How devices use SSID to connect to the internet

Whenever you setup a connected device for the first time, or when attempting to connect to a new network, you will be asked to configure your access to the internet. You will typically be prompted to scan for available networks in your area and choose the most appropriate for your needs, often a home or business Wi-Fi. These will show as either open and free of any immediate authentication checks (although these can come later through a browser), or locked, symbolised by a padlock symbol. If you wish to connect to a locked network, you will be asked to input a password before your computer attempts to contact the host.

However, this list of available networks will only show those that have been configured to publicly display their SSID or personalised name. To access any hidden networks you will need to input their SSID or name manually, alongside the password if necessary. To prevent a network from displaying on the list of available connections, you will need to choose ‘hidden’ or ‘disable SSID’ in the router’s settings.

Once your device is connected to a network, you can save its details and connect automatically each time you enable Wi-Fi.

SSID security

SSID is commonly used by most wireless networks globally. However, that doesn’t mean that it’s safe. In fact, it’s considered to be one of the least secure ways of connecting to a network. One common problem with SSID is that even if you select the option to have it hidden from other Wi-Fi users, modern software and apps make it possible for their users to discover any networks available – including yours.

Unfortunately, SSID can also contribute to falling victim of a cyber attack. In 2016, TalkTalk customers had their Wi-Fi passwords stolen by hackers in a Mirai malware attack which took down TalkTalk and the Post Office’s broadband networks. Hackers managed to reveal the routers’ SSID code, which in turn provided them with the information on where they were being used. Cyber criminals can also take advantage of data packets which have travelled through your device. If intercepted, they can use traces of the SSID to obtain personal information, including the name of the network you use.

Apart from being a potential security issue, an SSID can also be the source of aggravation and even neighbour disputes, especially if multiple other people in your apartment building or street use the same ISP – which is quite common, as sometimes one specific ISP is recommended in a given area. This could mean that multiple networks in a close proximity will have similar default SSIDs, especially if the network names are left unchanged. If unprotected, this could lead to devices connecting to networks belonging to someone else. Whether accidental or on purpose, the owner of the network could be left with having to cover the costs of someone else exceeding the download limits.