In 1985 the Federal Communication Commission released three bands of the radio spectrum: 900 MHz, 2.4 GHz, and 5 GHz. After these frequencies were opened to operate as license free wireless bands all kinds of consumer electronics began to use them, from walkie-talkies to baby monitors.
Shortly after this in the 1990s the IEEE (Institute of Electrical and Electronics Engineers) and the Wi-Fi Alliance were formed to help regulate these newly open frequencies and develop wireless technology.
The IEEE and Wi-Fi alliance soon saw a need for a set standard of protocols to be released so that the many new wireless devices could be manufactured to talk to each other .
To do this they came up with the 802.11 wireless standard. Before this manufactures built proprietary standards that could only talk to each other.
The first IEEE 802.11 standard was released in June 1997 and transferred data at the slow speed of 2 Mbps in the 2.4 GHz band.
In 1999 the IEEE released the 802.11a and 802.11b standards that were for many years the main standard used in Wi-Fi. 802.11a operated in the 5 GHz band while 802.11b operated in the 2.4 GHz band. 802.11a could transmit data at 54 Mbps while 802.11b moved data at 11 Mbps.
During this time wireless router began to be used in many homes. To encrypt these routers the IEEE used an authentication algorithm called WEP Wired Equivalent Privacy. In 2001 three researchers at Berkley found flaws in the RC4 encryption algorithm that WEP used.
They released a paper called “Security of WEP algorithm” which showed its many faults. After the release of the paper programs were written to take advantage of the flaws and widely shared on the internet. This made WEP opened to attacks as it was made easily hacked.
To make up for this in 2003 the Wi-Fi alliance announced WPA followed by WPA2 which both use the AES Advanced Encryption Standard instead of the RC4 encryption algorithm.
2003 also saw the introduction of 802.11g which worked in the 2.4 GHz range and could transmit at 54 Mbps.
802.11n was released in 2009. Often called wireless N it could transfer at speeds up to 300 Mbps.
Over the years the 2.4 GHz band had quickly becoming crowded. To fix this problem and plan for the future the IEEE created 802.11n to work in both the 2.4 GHz and 5 GHZ range.
802.11ac often called Gigabit Wi-Fi was released in December 2013 and works only in the 5 GHz band. It can transfer data at up to 750 Mbps.
WPA and WPA2 using AES are still the main encryption for Wi-Fi.
Extensions
In 2007 a extension was added on to Wi-Fi called WPS “Wi-Fi Protected Setup”. It was created to allow users to setup and connect to a router more easily. A serious flaw was found in WPS that would allow a attacker to brute force the pins WPS used as a exchange mechanism. Up to 10,000 pins are used by WPS as security. It was quickly discovered that 10,000 pins can be brute forced attacked within in 2-10 hours with a good signal.
Programs such as Reaver take advantage of this and are very successful at attacking a router when WPS is enabled. Many homes still use WPS since it allows for a easy setup of connecting a device to a router.