For computer network security, stealth wallpaper is a material designed to prevent an indoor Wi-Fi network from extending or "leaking" to the outside of a building, where malicious persons may attempt to eavesdrop or attack a network. While it is simple to prevent all electronic signals from passing through a building by covering the interior with metal, stealth wallpaper accomplishes the more difficult task of blocking Wi-Fi signals while still allowing cellphone signals to pass through.

The first stealth wallpaper was originally designed by UK defense contractor BAE Systems^[1] In 2012, The Register reported that a commercial wallpaper had been developed by Grenoble Institute of Technology and the Centre Technique du Papier with planned sale in 2013. This wallpaper blocks three selected Wi-Fi frequencies. Nevertheless, it does allow GSM and 4G signals to pass through the network, therefore allowing cell phone use to remain unaffected by the wallpaper.^[2]

• Electromagnetic shielding
• Faraday cage
• TEMPEST
• Wallpaper
• Wireless security

• Azcom: Stealth Wallpaper Prevents Wi-Fi Signals Escaping without Blocking Mobile Phone Signals
• The Register: Wifi Blocking Wallpaper