CS1: Wireless Communication and Mobile Programming Security Issues in Mobile Computing Dr. Khaled Mahmud Laurentian University International Global Experience Program Summer 2016

Agenda Information Security Security in WLAN Security Techniques and Algorithm Security Framework for mobile computing environment (c) Khaled Mahmud

Reference Chapter 20 [TEL] Data Communications and Networking- Behrouz A . Forouzan Web references (c) Khaled Mahmud

Wireless Security Broadcasting network traffic over the airwaves Has created an entirely new set of issues for keeping data transmissions secure (c) Khaled Mahmud

Risks of Mobile Computing Mobile computing devices Can store large amounts of data Are highly portable and, Are frequently unprotected Easy to steal or lose Unless precautions are taken, an unauthorized person can gain access to the information stored on them or accessed through them Even if not stolen or lost, intruders can sometimes gain all the access they need If the device is left alone and unprotected If data is "sniffed out of the air" during wireless communications, or If malware is installed (c) Khaled Mahmud http://www.stanford.edu/group/security/securecomputing/mobile_devices.html

Growth of Mobile Computing Mobile Computing in business Non-fixed/Flexing office space Working from home (or away) Bring Your Own Device (BYOD) Mobile Computing in education ‘Mobile programs’ Simulated labs Mobile Computing in personal life Flexible storage ‘More than eReaders’ in use Online billing/payment (c) Khaled Mahmud

Guideline for Corporate Use Dilemma: Productivity vs. Security For comprehensive mobile program companies can follow these guidelines Data encryption Password enforcement Device management Compliance and configuration management Data access Trust and confidence Enablement and ease of use (c) Khaled Mahmud http://www.htcpro.com/basic_principles.pdf

Security in Converged NW (c) Khaled Mahmud

Identity in Mobile Communication Authentication Identity management (c) Khaled Mahmud

Authentication Credentials Types of authentication credentials What you have Example: key fob to lock your car What you are Example: facial characteristics recognized by health club attendant What you know Example: combination to health club locker Khaled Mahmud

Example Khaled Mahmud

Multifactor Security What you have What you know What you are Physical key Magnetic ID card Hardware token RFID badge What you know Password/passphrase/PIN Personal question/answer Predetermined events What you are Fingerprint Voice recognition Retinal scan Face recognition (c) Khaled Mahmud

What You Know: Passwords User logging in to a system Asked to identify himself User enters username User asked to authenticate User enters password Passwords are most common type of authentication today Passwords provide only weak protection Khaled Mahmud

What You Have: Tokens and Cards Small devices with a window display Synched with an authentication server Code is generated from an algorithm Code changes every 30 to 60 seconds Khaled Mahmud

What You Are: Biometrics Standard biometrics Uses person’s unique physical characteristics for authentication Fingerprint scanners most common type Face, hand, or eye characteristics also used Fingerprint scanner types Static fingerprint scanner Takes picture and compares with image on file Dynamic fingerprint scanner Uses small slit or opening Khaled Mahmud

Identity Management Various IDs Apple ID Windows live ID/Hotmail ID/Skype ID/ Google ID Facebook ID Bank/School/Insurance/Utility Services We can use a single authentication credential shared across multiple networks Called Federated Identity Management (FIM) when networks are owned by different organizations Single Sign-On (SSO) holds promise to reduce burden of usernames and passwords to just one Khaled Mahmud

Account Management Managing user account passwords Can be done by setting password rules Too cumbersome to manage on a user-by-user basis Security risk if one user setting is overlooked Preferred approach: assign privileges by group Microsoft Windows group password settings Password Policy Settings Account Lockout Policy Khaled Mahmud

Attacks Against WLANs Some of the most dangerous attacks Hardware theft Device may contain information that can assist someone in breaking into the network AP impersonation A rogue AP can impersonate a valid device Passive monitoring Data transmissions can be monitored Denial of service (DoS) Flood the network with transmissions and deny others access to the AP (c) Khaled Mahmud

Types of Wireless LAN Attacks Discovering the network Attacks through the RF spectrum Attacks involving Access Points (c) Khaled Mahmud

Discovering the Network One of first steps in attack is to discover presence of a network Beaconing AP sends signal at regular intervals to announce its presence and provide connection information Wireless device scans for beacon frames War driving Process of passive discovery of wireless network locations (c) Khaled Mahmud

Attacks Through the RF Spectrum Using Wireless protocol analyzer Generating interference (c) Khaled Mahmud

Wireless Protocol Analyzer Wireless traffic captured to decode and analyze packet contents Network interface card (NIC) adapter must be in correct mode Six modes of wireless NICs Master (acting as an AP) Managed (client) Repeater Mesh Ad-hoc Monitor (c) Khaled Mahmud

Interference Signals from other devices can disrupt wireless transmissions Devices that can cause interference with a WLAN Microwave ovens Bluetooth devices Elevator motors Copy machines Outdoor lighting (certain types) Theft protection devices (c) Khaled Mahmud

Attacker Interference (c) Khaled Mahmud

802.11 Security Original IEEE 802.11 committee recognized wireless transmissions could be vulnerable Implemented several wireless security protections in the standard Left others to WLAN vendor’s discretion Protections were vulnerable and led to multiple attacks Initial Approaches MAC Address Filtering SSID Broadcast (hide) Wired Equivalent Privacy (WEP) (c) Khaled Mahmud

MAC Address Filtering Method of controlling WLAN access Limit a device’s access to AP Media Access Control (MAC) address filtering Used by nearly all wireless AP vendors Permits or blocks device based on MAC address Vulnerabilities of MAC address filtering Addresses exchanged in unencrypted format Attacker can see address of approved device and substitute it on his own device Managing large number of addresses is challenging (c) Khaled Mahmud

SSID Broadcast Each device must be authenticated prior to connecting to the WLAN Open system authentication Device discovers wireless network and sends association request frame to AP Frame carries Service Set Identifier (SSID) User-supplied network name Can be any alphanumeric string 2-32 characters long AP compares SSID with actual SSID of network If the two match, wireless device is authenticated (c) Khaled Mahmud

Wired Equivalent Privacy (WEP) IEEE 802.11 security protocol Encrypts plaintext into ciphertext Secret key is shared between wireless client device and AP Key used to encrypt and decrypt packets WEP can only use 64-bit or 128-bit number to encrypt (c) Khaled Mahmud

Newer Wireless Security Solutions Unified approach to WLAN security was needed IEEE and Wi-Fi Alliance began developing security solutions Resulting standards used today IEEE 802.11i WPA and WPA2 (c) Khaled Mahmud

Wi-Fi Protected Access (WPA) Introduced in 2003 by the Wi-Fi Alliance A subset of IEEE 802.11i Design goal: protect present and future wireless devices Temporal Key Integrity Protocol (TKIP) Encryption Used in WPA Uses longer 128 bit key than WEP Dynamically generated for each new packet (c) Khaled Mahmud

Preshared Key (PSK) Authentication After AP configured, client device must have same key value entered Key is shared prior to communication taking place Uses a passphrase to generate encryption key Must be entered on each AP and wireless device in advance Not used for encryption Serves as starting point for mathematically generating the encryption keys (c) Khaled Mahmud

Wi-Fi Protected Access 2 (WPA2) Second generation of WPA known as WPA2 Introduced in 2004 Based on final IEEE 802.11i standard Uses Advanced Encryption Standard (AES) Supports both PSK and IEEE 802.1x authentication (c) Khaled Mahmud

IEEE 802.11i Define a Robust Security Network Association (RSNA) Provide Mutual authentication between client devices and AP Controlled access to the network Establishment of security keys Key management (c) Khaled Mahmud

IEEE 802.1x Client device must be authenticated on the network by an external authentication server Remote Authentication Dial In User Service (RADIUS) All communication between the client device and the AP is blocked Until the authentication process is completed 802.1x uses the Extensible Authentication Protocol (EAP) For relaying access requests between a wireless device, the AP, and the RADIUS server (c) Khaled Mahmud

IEEE 802.1x Authentication Originally developed for wired networks Provides greater degree of security by implementing port security Blocks all traffic on a port-by-port basis until client is authenticated (c) Khaled Mahmud

AAA Server Authentication, Authorization and Accounting (AAA) Most popular server RADIUS (Remote Authentication Dial In User Service) Newer protocol Diameter Allows data roaming Mobile computing (c) Khaled Mahmud