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Without wires IMKE SPI2009 Kaido Kikkas. WiFi – what's that? ● Actually a trademark of the Wi-Fi Alliance or WECA (Wireless Equipment Compatibility Alliance)

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Presentation on theme: "Without wires IMKE SPI2009 Kaido Kikkas. WiFi – what's that? ● Actually a trademark of the Wi-Fi Alliance or WECA (Wireless Equipment Compatibility Alliance)"— Presentation transcript:

1 Without wires IMKE SPI2009 Kaido Kikkas

2 WiFi – what's that? ● Actually a trademark of the Wi-Fi Alliance or WECA (Wireless Equipment Compatibility Alliance) ● Technically a set of wireless networking protocols developed by IEEE (Institute of Electrical and Electronics Engineers) ● A large component in today's new media structure – on Jan 28, 2009 Estonia had 1174 hotspots registered by http://www.wifi.ee ● PC, PDA, smartphones (incl. specialised ones)

3 WiFi protocols ● Protocol Date Op. Freq. Typ. Rate Max Rate Range (Indoor) Legacy 1997 2.4 -2.5 GHz 1 Mbit/s 2 Mbit/s ? 802.11a 1999 5.15-5.35/ 5.47-5.725/ 5.725-5.875 GHz 25 Mbit/s 54 Mbit/s ~50m 802.11b 1999 2.4-2.5 GHz 6.5 Mbit/s 11 Mbit/s ~100m 802.11g 2003 2.4-2.5 GHz 11 Mbit/s 54 Mbit/s ~100m 802.11n 2006 2.4 GHz or 5 GHz bands 200 Mbit/s 540 Mbit/s ~50m

4 Advantages over wired networks ● CAMP: Convenience, Affordability, Mobility, Productivity ● Installation flexibility, speed and scalability ● Good for regions without or with limited wired infrastructure ● Have a better chance of surviving disasters ● Promise high bandwidths, global mobility, quality of service and seamless integration

5 Disadvantages ● Security(esp. when combined with clueless users) ● Radio wave limitations, can be interrupted ● Speed ● Network latency (package loss) ● Standards and interoperability – strived for, but not always achieved (proprietary extensions) ● Equipment is global, laws and standards are not

6 History ● 1896 – Marconi's radio and the Wireless Telegraph and Signal Company Limited ● 1901 – radio connection over the Atlantic Ocean ● WWII – encrypted radio ● 1950s – first radio telephone networks by Bell ● 1971 – ALOHANET, the first WLAN ● 1982 – first mobile networks ● 1997 – IEEE 802.11 (the initial, Legacy version)

7 Two variants ● Access point (bridge or router) and clients ● Ad-hoc (peer to peer)

8 WEP ● Wired Equivalent Privacy, 1999 ● Easily implemented, robust (against latency), moderate security using secret keys (first 10, later 26 hex characters) ● Initially only 40-bit encryption: no export limitations in the US (later 128-bit) ● NB! Any WEP key can be cracked with readily- available software (e.g. Kismet and Aircrack) in a couple of minutes

9 WPA ● Wi-Fi Protected Access 2003 ● Improved encryption, implemented a subset of the IEEE 802.11i standard (see next)

10 WPA2 ● 2004, IEEE certified full standard (802.11i) ● Several steps of authentication, considered secure ● Problem: needs individual passphrases => cannot be used for public hotspots (pubs, hotels)

11 Main threats ● Direct intrusion – attacks against the LAN itself ● Unauthorised use – using as an attack platform – engaging in the not-so-nice Internet activities (pedophiles, harassers, distortionists, scammers and spammers)

12 Countermeasures ● Consider the range ● Use directional antennas and/or special materials to limit emission ● Use stronger protection (WPA2) ● Do not forward the SSID ● Use MAC registration ● Change the name, username and password of the WiFi router (typical: linksys, admin, admin/1234)

13 Wardriving, warwalking and warchalking ● 1983 movie War Games => wardialing ● Wardriving (-biking, -flying, -walking....) ● Legally grey area (mostly unregulated) ● Warchalking – Matt Jones 2002, inspired by American traditional hobo symbols. Did not catch on well, due to some companies hijacking the symbols

14 Warchalk symbols

15 That's all


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