Wireless Networks

1. Wireless Networks Standards and Security

2. Wireless Networks • Most consumer based wireless products conform to IEEE standards • 802.11[x] where x is a letter a-ai • Ratified standards/protocols are 802.11a, b, g, n • Standards measured and defined with ISM band, throughput, and range (generally) • ISM Band defines the frequency at which radio transmissions occur (in a MHz or GHz range). • Throughput is how many packets can be sent in a certain time period (how much data can you send in a second) • Range is how far away two communication devices can be from each other

3. 802.11a,b,g,n Protocols

5. Channels • Wireless networks also have channels in a certain frequency • Very similar to channels on a TV station • Allocated by country • For example, the 2.4GHz range is divided into 13 channels (14 for Japan)

6. Channels

7. Wireless vs Wired

8. Wireless Interference • Other devices operate on the same ISM band • Microwaves • Baby monitors • Cordless phones • These sources of interference can interfere and weaken the signal • Limited range – signal attenuation • Wired still has signal attenuation, but is more reliable

9. Concept of Wireless • You don’t have to plug your computer in somewhere • Freedom to roam (especially at Eastern – can just carry a laptop from building to building) • Slower transfer rates and throughput on average than wired connections.

10. Security • You send the data over the network, wirelessly • Communication between the computer and the router • And someone else? • Well, it is a radio signal after all. You have a transmitter and a receiver. • Wired connections are usually end to end, and are harder to “tap”

11. So encryption comes in • And solves two problems: • You don’t want people connecting to your network? Put a password on it. • This password or key will then be used to encrypt traffic so it cannot be “sniffed” or captured • A few types of encryption • None • WEP – easily cracked • WPA – backwards compatible with WEP and can be cracked • WPA2– currently cannot be cracked simply

13. Plain text or no encryption • Person who is sniffing the wireless traffic can pick up anything and everything being sent. • Usernames • Passwords • Sites you are visiting • Instant messages • Emails • etc

14. Firesheep • An addon for firefox • Looks for any social networking sites and session id’s that are sent over unencrypted connections • Attacker gets list of people who logged in (usually over unsecured wireless) and can then go and wreak havoc using their profile. • People realize this, change their passwords, and then continue using their profiles – and get hacked AGAIN.

15. Sidejacking • Sidejacking refers to taking someone else’s browsing session and applying it to themselves, pretending to be the other person • Usually works by finding a session id (can be found in a cookie) • Cookie – a piece of data that a website copies over to your computer • Used to re-authenticate a user from page to page on a website without having them login each time they load a new page.

16. Sidejacking example user Router (to internet) Hacker / sniffer = cookie

17. How do you protect yourself? • Use encryption on wireless • Hard to make public wifi set this up (Starbucks, EWU…) • Encryption on wireless won’t work if you share the password with someone else, because they can decrypt your packets (harder to do with WPA2) • Use encryption as a protocol • HTTPS, FTPS • Firefox addon: HTTPS Everywhere – forces SSL on common sites (and made by EFF) • Use a VPN and route your traffic through it • Also a level of encryption • VPN server needs to be set up or paid for – roughly $50 a year commercially