The communications over wifi links have been realizable for a very long time. Radios were used for Communications in the late 1800s. Guglielmo Marconi demonstrated the transmission of Morse Code over wireless links for the British Post Office in 1897. In 1898, the Russian navy cruiser Africa used a wireless Communicating device to communicate with operators on shore. TV signals were first broadcast in 1928. The very first visual picture sent over TV signals was Felix the Cat.

Since those times, radio Communicating have come a long way. Commercial radio stations, television broadcasts, cellular phone networks, satellite data-links, slow-scan amateur video transmissions, baby monitors, Unmanned Aerial Vehicles (UAV), and GPS navigation systems all practice wireless technology.

The practice of encryption in Communications is nothing new either. In fact, it’s been used for centuries to protect sensitive messages, such as those sent from Caesar to his battlefield generals. The famous Enigma cipher machine was used during World War II to encrypt radio Communications. Communicating for television transmissions were encrypted with VideoCipher II in 1986. VideoCipher systems often used DES for video encryption. In 2001, the National Institute of standards and Technology (NIST) in the United States selected Rijndael as a federal replacement for DES, thus naming Rijndael the new Advanced Encryption Standard (AES). AES has been incorporated in publicly available wireless Communications devices as one of the algorithms for WPA. Some attempts are now available for AES, such as timing attacks that exploit the properties of certain types of hardware. Data encryption and Communications security continue to remain an active area of research to this day.

Basic principles of Wireless

The added convenience and capabilities offered by wireless are not without a price, however. By offering new features and allowing for distributed operation, threats against the systems connected to wireless networks have increased. Break-ins to wireless networks are on the rise. The accessibility of wireless Communicating equipment has led to the proliferation of wireless networks and individuals who attack them. As wireless equipment becomes more ubiquitous, the economic system of scale allows more people to acquire the hardware necessary to mount an attack against that equipment. The increasing amount of information and services available through wireless networks makes the systems connected to them much more attractive targets.

What is Wifi ?

In order to understand the new threats a wireless network can pose, a basic understanding of radio frequency transmission and the technologies currently used to handle wireless Communications is necessary.

Wireless equipment uses radio frequencies to communicate. These are electromagnetic emissions in the range of 3 Hz to 300 GHz. Although it creates electromagnetic emissions, a microwave oven is generally not considered a wireless device, as the radio waves are not used to communicate (sans firing a microwave oven at someone with a trebuchet). However, radio frequencies generated by other equipment are used for Communications, such as those from cellular phones and Wi-Fi cards. These radio frequencies are received by the devices you want to communicate with to transmit information. They can also be received by devices you don’t want to communicate with, exposing sensitive information.

Normalization and regulation of wireless technology

Radio frequency transmissions are regulated by various organizations based on geographic limit. At the world level, the International Telecommunications Union (ITU) coordinates the allocations of radio frequencies, and within the U.S., the Federal Communications Commission (FCC) regulates and enforces radio frequency allotments. The regulation of radio transmissions by the various regional bodies ultimately affects the design and deployment of wireless networks. Radio frequency propagation issues that are present in one regional area may not be an issue in another due to regional allocations. For example, the frequencies from 222 MHz through 225 MHz are available for some amateur radio use in the U.S., but in the U.K., those frequencies are marked for military practice. As such, wireless twist manufacturers have to be cognizant of regional differences so users of the devices are within regulatory compliance for their region.

The wireless standards recognize these regional differences and specify frequency allocations and transmission standards that allow interoperability within the various regulatory domains. The Institute of Electric and Electronics Engineers (IEEE) has taken these regional differences into account when designing and ratifying wireless networking measures. One visible aspect of these regulatory controls is the numbering of transmission channels in the IEEE 802.11X measures (the “X” in 802.11X is a placeholder for other letters; there is no 802.11X standard per se). Different restrictive domains have access to different channels, and the numbering of channels may be discontinuous when viewed by the user. When examining the list of available wireless lines on 802.11 devices, you might have noticed certain channel numbers are “missing”; the missing channels are transmission bands removed or disabled due to regional emissions regulations.

Bluetooth

Bluetooth is another common wireless Communications protocol. The Bluetooth protocol is often used for devices such as cellular phones, headsets, digital cameras, and other devices not often viewed as being “computers.” Wireless headsets for cellular phones are often Bluetooth devices. Cellular phones that offer calendar and address book synchronization capabilities with software running on a user’s laptop often employ the Bluetooth protocol. You can practice a keyboard and mouse over the protocol as well, employing Bluetooth to connect them to the computer.

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