Wireless Encryption By: Kara Dolansky Network Management Spring 2009

Introduction What is Wireless Encryption? Why Encrypt? History OSI Model Types of Encryption How it works ProtocolsCracking Authorities / Standards

What is Wireless Encryption? General method of scrambling data Data is transformed to be unintelligible Invisible to the end user Operates independently of any other encryption processes Data is encrypted ONLY while in transit

Why Encrypt? Unauthorized Individuals may: Use up your bandwidth Use up your bandwidth Access files without authorization Access files without authorization Freely eavesdrop without making a connection Freely eavesdrop without making a connection Private correspondence Sensitive company information

Why Encrypt? Security: Personal data & passwords Personal data & passwords Credit Card information Social Security Numbers Bank Account information Protect your PC and files Protect your PC and files Protect classified information Protect classified information Identity theft or MAC spoofing

History Cryptography began ~2000 B.C. in early Egyptian days in early Egyptian days It has been used for War, Diplomacy, & Politics Diplomacy, & Politics Originally used with computers for confidential government data: military use Currently, all sensitive data is encrypted (or at least should be!)

OSI Model Encryption is a network security process Applies crypto services at the network transfer layer

Types of Encryption End to End: Message is encrypted when it is transmitted & decrypted when it is received Message is encrypted when it is transmitted & decrypted when it is received Message remains encrypted from start to finish Message remains encrypted from start to finish It is efficient (the network does not need to have special encryption facilities) It is efficient (the network does not need to have special encryption facilities) Disadvantage: Only secures the contents Disadvantage: Only secures the contents

Types of Encryption Link: Message is encrypted when transmitted but decrypted each time it passes through nodes Message is encrypted when transmitted but decrypted each time it passes through nodes More convenient in networks with many nodes More convenient in networks with many nodes Encrypts all information (headers & routing info.) Encrypts all information (headers & routing info.) Disadvantage: more points of vulnerability Disadvantage: more points of vulnerability

How it Works Keys are the basic concept of encryption Complex mathematical formulas (algorithms) Complex mathematical formulas (algorithms) Data passes through algorithms & is converted into ciphertext Keys make it difficult for individuals to crack the encrypted message

How it Works Two Key Systems: Secret Key Secret Key Both sender & receiver know secret code word This is not feasible for business transactions Fast but not as safe as public key Public Key (Asymmetric) Public Key (Asymmetric) Key pairs are used to encrypt & decrypt messages Each person has public key & private key Public key is useless without the private key

How it Works

Message Authentication: Ensures sent & received message is in exact form Ensures sent & received message is in exact form Digital Signature: Tool that provides electronic evidence that you sent a signed message Tool that provides electronic evidence that you sent a signed message

Protocols Encryption is implemented through IPsec (Internet Protocol Security) IPsec works through the network architecture SSL (Secure Sockets Layer): Public key encryption developed by Netscape Public key encryption developed by Netscape Symmetric protocol Symmetric protocol Used by Internet browsers & web servers to transmit sensitive information Used by Internet browsers & web servers to transmit sensitive information By default, browsers have 40-bit encryption By default, browsers have 40-bit encryption SSL has become part of TLS (Transport Layer Security) SSL has become part of TLS (Transport Layer Security)

Protocols Wireless Equivalent Privacy (WEP): Introduced in 1997 Introduced in 1997 Most common security protocol in older networks Most common security protocol in older networks Key lengths of 128- & 256-bit Key lengths of 128- & 256-bit Used at lowest Used at lowest layers of OSI model Weaknesses Weaknesses were identified in 2001

Protocols Wi-Fi Protected Access (WPAv1): Rolled out after WEP to provide much stronger data encryption Rolled out after WEP to provide much stronger data encryption Introduced in 2003 Introduced in 2003 All of the network devices need to be configured for WPA All of the network devices need to be configured for WPA Temporal Key Integrity Protocol (TKIP) encryption algorithm developed for WPA Temporal Key Integrity Protocol (TKIP) encryption algorithm developed for WPAWPAv2: Implements mandatory elements of i Implements mandatory elements of i Combines AES & TKIP algorithm, considered fully secure Combines AES & TKIP algorithm, considered fully secure

Wireless Encryption Cracking What is it? Breaching of wireless encryptions Breaching of wireless encryptions Types of Attacks: Decrypting traffic by tricking access points Decrypting traffic by tricking access points Gathering traffic & performing dictionary-based attacks Gathering traffic & performing dictionary-based attacks Decrypting traffic by statistical analysis Decrypting traffic by statistical analysisExamples: WEPCrack, AirCrack, AirSnort WEPCrack, AirCrack, AirSnort

Encryption Humor

Authorities / Standards Data Encryption Standard (DES): Approved in 1976 & publicized in 1977 Approved in 1976 & publicized in st major symmetric algorithm developed for PC’s 1 st major symmetric algorithm developed for PC’s Official method for protecting unclassified data Official method for protecting unclassified data Advanced Encryption Standard (AES): Adopted in 2001 by U.S. Government Adopted in 2001 by U.S. Government Uses 128-, 192-, or 256-bit keys Uses 128-, 192-, or 256-bit keys 2009, AES is the most popular algorithm used in symmetric key cryptography 2009, AES is the most popular algorithm used in symmetric key cryptography

Authorities / Standards IEEE series of standards (1997): Set of standards carrying out WLAN PC communication Set of standards carrying out WLAN PC communication : two net bit rates of 1 or 2 Mbit/s & forward error correction b: maximum raw data rate of 11 Mbit/s g: maximum physical layer bit rate of 54 Mbit/s n: new multi-streaming modulation technique; still under draft development

TheEnd