830 likes | 836 Views
Wireless, and Security. CS 1 Rick Graziani Cabrillo College Spring 2017. 1981 primitive Internet report on KRON. http://www.youtube.com/watch?v=5WCTn4FljUQ&feature=player_embedded. Circuit Switched.
E N D
Wireless, and Security CS 1 Rick Graziani Cabrillo College Spring 2017
1981 primitive Internet report on KRON http://www.youtube.com/watch?v=5WCTn4FljUQ&feature=player_embedded Rick Graziani graziani@cabrillo.edu
Circuit Switched • Circuit Switching:A form of data communication which establishes a single connection or circuit between source and destination to carry the data stream. • Like a conventional telephone system. • When a subscriber makes a telephone call the dialed number is used to set switches in the exchanges along the route of the call so that there is a continuous circuit from the originating caller to that of the called party. Rick Graziani graziani@cabrillo.edu
The range of G.fast will be very short — on the order of 250 meters (820 feet). Basically, G.fast is envisaged as the ideal way of getting fiber-like speeds from the cabinet, manhole, or telephone pole. Rick Graziani graziani@cabrillo.edu
Packet Switching • Packet Switching: A form of data communications which breaks a data stream into small sections, sends them separately by the best available channels and reassembles the original data stream at its destination. • An alternative is to allocate the capacity to the traffic only when it is needed, and share the available capacity between many users. Rick Graziani graziani@cabrillo.edu
Wireless Access Point • A wireless access point is a device that connects wireless devices (laptops, etc.) to a wired network, usually an Ethernet LAN. Rick Graziani graziani@cabrillo.edu
Wireless Access Point • In our example the wireless access point (AP) will include a Router. Rick Graziani graziani@cabrillo.edu
Configuring the AP and Router Wireless Settings: • SSID (Service Set Identifier) – Name of your network • Security: WPA2, WPA, WEP, or none SSID Rick Graziani graziani@cabrillo.edu
Configuring the AP and Router Wireless Settings: • Security: WPA2, WPA, WEP, or none WPA2 Rick Graziani graziani@cabrillo.edu
SSID • The SSID is what will be displayed when people with wireless computers are looking for a wireless LAN. Rick Graziani graziani@cabrillo.edu
Linksys WRT54G Router Information • IP Address from ISP • Connects to your DSL/Cable Modem • NAT (Network Address Translation) Local Network • Ethernet Switch • Connect “wired” computers • DHCP Server (optional) Wireless • SSID: MyHomeNetwork • DHCP Server: (optional) • Channel: 11 • Encryption Function: WPA Rick Graziani graziani@cabrillo.edu
You choose… • There are many resources to discuss the possible health risks or wireless LANs. • As a networking and WLAN user and instructor I have my own thoughts which I will share. • If you are concerned, then research the information and come to your own conclusions. • The following information is from my own research and experience. Rick Graziani graziani@cabrillo.edu
Wireless Frequency • Wireless APs operate at: • 2.4 GHz • 5 GHz • 2 GHZ! That’s the same as my microwave oven, isn’t that dangerous? • Answer: No. • Electromagnetic waves happen naturally. • Light is an electromagnetic wave • It is not the frequency, but the wattage, the power. • Any electromagnetic wave can be dangerous with too much power. • A 25 watt light bulb is safe, but it wouldn’t be safe at 250,000 watts • Wireless access points generate signals at 1/10th of a watt. • Like all electromagnetic waves, the signal does not fade in a linear manner, but inversely as the square of the distance. Rick Graziani graziani@cabrillo.edu
www.britishlibrary.net Rick Graziani graziani@cabrillo.edu
Inverse square law 10 20 30 40 50 100 • Double the distance of the wireless link, we receive only ¼ of the original power. • Triple the distance of the wireless link, we receive only 1/9 the original power. • Move 5 times the distance, signal decreases by 1/25. Point A 10 times the distance 1/100 the power of A 3 times the distance 1/9 the power of Point A 2 times the distance ¼ the power of Point A 5 times the distance 1/25 the power of Point A Rick Graziani graziani@cabrillo.edu
Putting it in some perspective • Measurements from an antenna transmitting 100mW at 1 inch • Remember a milliwatt is 1/1,000th of a Watt • Microwave oven typically operates at 1,000 watts in a confined space. 1” 100 mW 1/10th watt 2” 25 mW 1/40th watt 4” 6.25 mW 1/166th watt 8” 1.56 mW 1/1000th watt 16” 0.39 mW 4/10,000th watt 32” 0.097 mW 1/10,000th watt 64” (5.3 ft) 0.024 mW 2/100,000th watt 128” (10.6 ft) 0.006 mW 6/1,000,000th watt 256” (21.3 ft) 0.0015 mW 15/10,000,000th watt • Light bulbs would also be dangerous the were 10,000 to 1,000,000,000,000 stronger. • A 250,000 watt up to a 250,000,000,000,000 watt light bulb would also be dangerous. Rick Graziani graziani@cabrillo.edu
Wireless N and ac • Wireless N provides better speeds (bandwidth – 450 Mbps) and better range by utilizing multiple antennas. Backwards compatible with 802.11 b and g. 802.11ac uses 5Ghz band –1300 Mbps and more Rick Graziani graziani@cabrillo.edu
Wireless Security – Everyone can hear • Others can “hear” or capture your information. • Wireless signals are propagated, sent, similar to our voice sound waves. Rick Graziani graziani@cabrillo.edu
Cell Phones do not cause explosions • http://www.youtube.com/watch?v=OQ0aTMMITp8 • http://www.youtube.com/watch?v=NRGrFLRs9xE&feature=related Rick Graziani graziani@cabrillo.edu
Wireless Security – Everyone can hear • If we don’t want them to understand what they hear, we can encrypt or code the information. • As long a our wireless computer and access point are using the same encryption algorithm, such as WPA2. • Make your Pre-Shared Key over 25 characters long and make it random Rick Graziani graziani@cabrillo.edu
Cryptology • From the Greek kryptós, "hidden," and lógos, "word“ • Is the science of secure (or, generally speaking), secret communication Cryptography • The branch of applied mathematics that concerns itself with transforming messages into seemingly unintelligible forms and back again so it cannot be viewed by unauthorized users Rick Graziani graziani@cabrillo.edu
Cryptography is the process of converting plaintext into ciphertext (unreadable text) by using an encoding function, such as an encryption algorithm or a secret list of substitution characters Rick Graziani graziani@cabrillo.edu
Examples of Applied Cryptography • Phone cards, cell phones, remote controls • Cash machines, money transfer between banks • Electronic cash, online banking, secure email • Satellite TV, pay-per-view TV • Digital Rights Management (DRM) • Etc., etc… Rick Graziani graziani@cabrillo.edu
Benefits of Cryptography Protections provided: • Confidentiality • Authentication • Integrity Rick Graziani graziani@cabrillo.edu
Characteristics of a Secure VPNs Authentication • Verify the sender • Trust the sender is whom they claim to be • Ensures that a message: • comes from an authentic source and • goes to an authentic destination Rick Graziani graziani@cabrillo.edu
Characteristics of a Secure VPNs Data confidentiality • Allows only authorized users to access the Information • Protecting data from eavesdroppers • Aims at protecting the message contents from being intercepted by unauthenticated or unauthorized sources. Rick Graziani graziani@cabrillo.edu
Characteristics of a Secure VPNs Data integrity • Trust the information has not been altered • Across the Internet, there is always the possibility that the data has been modified. • Data integrity guarantees that between the source and destination: • No tampering or alternation to data • digital signatures Rick Graziani graziani@cabrillo.edu
Encryption: changing the original text to a secret message using cryptography • Decryption: reverse process of encryption Rick Graziani graziani@cabrillo.edu
Algorithm: mathematical procedure that works with a key to generate ciphertext from plaintext input • AKA cipher Rick Graziani graziani@cabrillo.edu
Key: is a mathematical value (e.g., word, number, phrase) that determines how a plaintext message is encrypted to produce ciphertext • Its possession is required to decrypt the ciphertext and recover the original message Rick Graziani graziani@cabrillo.edu
Key Length: keys have a corresponding key length (or key size): which is the number of bits, or sometimes bytes, in the key • Key lengths tend to be huge numbers a 2-bit key has 4 values in its key space (00, 01, 10, 11) • Generally, the larger the key length, the more secure the ciphertext Rick Graziani graziani@cabrillo.edu
Wireless Security • Your web browsing or email access should already be secured. • HTTPS - Look for the lock Rick Graziani graziani@cabrillo.edu
Pop-ups (Wikipedia.org) • Banner Ads first used by Yahoo. • Most users regard pop-ups as a nuisance. • In the early 2000s, all major web browsers except Internet Explorer allowed the user to block pop-ups almost completely. Ultimate irony! Rick Graziani graziani@cabrillo.edu
Pop-up, looks real… http://www.news3insider.com/finance/google-hiring-you.html Rick Graziani graziani@cabrillo.edu
C/NET – Pop-ups mean more $$$ • Publishers willingly allow pop-ups or pop-unders because they command higher prices, and they're in high demand by advertisers. Rick Graziani graziani@cabrillo.edu
But are the clicks real or bots? Rick Graziani graziani@cabrillo.edu
Spyware (Wikipedia.org) • Spyware is computer software that gathers and reports information about a computer user without the user's knowledge or consent. • May perform many different functions, including: • Delivery of unrequested advertising (pop-up ads in particular), • Harvesting private information • Re-routing page requests to illegally claim commercial site referral fees • Spyware or Malware Can include: • keystroke loggers • denial-of-service (DoS) attack agents Rick Graziani graziani@cabrillo.edu
Cookies • A cookie is information sent by a server to a browser and then sent back to the server each time it accesses that server. • Amongst other uses, cookies enable websites to be customized for individual users once browsing patterns have been established. • Cookies only store information that you provide. Rick Graziani graziani@cabrillo.edu
First time you login HTTP Requests: GET (first time) HTTP: Response Set-cookie: ID 5551212 HTTP Server HTTP Requests (GET) now include ID - 5551212 HTTP Client Web server can now track clients activities on the web site. Rick Graziani graziani@cabrillo.edu
Each time you login… HTTP: Cookie 5551212 included HTTP Server HTTP data customized for Rick Graziani HTTP Client Rick Graziani graziani@cabrillo.edu
Cookies - Purpose • Typically this is used to authenticate or identify a registered user of a web site as part of their first login process or initial site registration without requiring them to sign in again every time they access that site. • Other uses are maintaining a "shopping basket" of goods selected for purchase during a session at a site, site personalization (presenting different pages to different users), and tracking a particular user's access to a site. Rick Graziani graziani@cabrillo.edu
Cookies - Permissions • A browser may or may not allow the use of cookies. • The user can usually choose a setting. • Microsoft Internet Explorer • Tools > Internet Options > Privacy Tab • Use slider to set options, or use advanced options Rick Graziani graziani@cabrillo.edu
http://techguylabs.com/ Rick Graziani graziani@cabrillo.edu
Phishing… Rick Graziani graziani@cabrillo.edu