27 Mhz Wireless Keyboard Analysis Report aka “We know what you typed last summer”.
You can download it from the following link: https://packetstormsecurity.com/files/download/61421/27_Mhz_keyboard_insecurities.pdf
Source: https://packetstormsecurity.com/files/61421/27_Mhz_keyboard_insecurities.pdf.html