Network Security Peter Behrens Seth Elschlager

Computer Security Preventing unauthorized use of your network and information within that network. Preventing unauthorized use of your network and information within that network. Helps ensure your privacy Helps ensure your privacy Detection of unauthorized access to your network Detection of unauthorized access to your network Trace what they did while on the network Trace what they did while on the network

Security Code Writers Try to improve security all the time. Code Writers Try to improve security all the time. There is no completely secure system. There is no completely secure system. Since programming is math based, if you have the key, you have access to the system. Since programming is math based, if you have the key, you have access to the system.

Reasons They Want Access Hide Their Location Hide Their Location Gain access to your information Gain access to your information Fun Fun Challenge Challenge To Modify, or Destroy your Software To Modify, or Destroy your Software

What is at risk? Confidentiality- Confidentiality- Information should be available only to those who rightfully have access to it. Information should be available only to those who rightfully have access to it. Examples: Examples: Credit Card Numbers Credit Card Numbers Bank Account Information Bank Account Information Passwords Passwords

What is at risk? Integrity- Integrity- The information should be modified only by those who are authorized to do so. The information should be modified only by those who are authorized to do so. Examples: Examples: Database Administrators should be the only ones modifying the database. Database Administrators should be the only ones modifying the database.

What is at risk? Availability- Availability- Information should be accessible to those who need it when they need it. Information should be accessible to those who need it when they need it. Examples Examples Facts Facts Reports Reports Company Data Company Data Personal Data Personal Data

Who do these apply to? These apply to home users as well as professional users… These apply to home users as well as professional users… You don’t let a stranger ruffle through your bank statements. You don’t let a stranger ruffle through your bank statements.

Risk Management Probably can’t plan for every threat Probably can’t plan for every threat Threats may be accidental or intentional Threats may be accidental or intentional

Unfortunately, limited resources can cripple a fully functional system. Unfortunately, limited resources can cripple a fully functional system. Core processes Core processes OS failures OS failures Viruses Viruses By using malicious software, someone can flood your network resources and cripple your system. By using malicious software, someone can flood your network resources and cripple your system.

Denial Of Service Attack Most common attack Most common attack May be part bigger attack, or may stand alone. May be part bigger attack, or may stand alone. Prevents authorized users the use of network services by flooding the network with junk traffic. Prevents authorized users the use of network services by flooding the network with junk traffic.

Cont’d Once a “bad guy” has access to a system, he can then use echo functions and acknowledgement functions to send useless data back and forth across the network. This will use up network capacity and bandwidth, slowing the network to almost unusable. Once a “bad guy” has access to a system, he can then use echo functions and acknowledgement functions to send useless data back and forth across the network. This will use up network capacity and bandwidth, slowing the network to almost unusable.

Connectivity Attacks Some attacks are executed to prevent connections from establishing. Some attacks are executed to prevent connections from establishing. Kernels establish one connection at a time. If a connection is not completed, a new connection will not be created/enabled. Kernels establish one connection at a time. If a connection is not completed, a new connection will not be created/enabled. Example Example SYN Flood Attack SYN Flood Attack

SYN Flood Attack The attacker gains a connection to the victim’s machine. The connection is only half completed, and the kernel is left waiting for a finished connection. The attacker gains a connection to the victim’s machine. The connection is only half completed, and the kernel is left waiting for a finished connection. The user is then prohibited from making a legitimate connection until the “dummy” connection is completed. The user is then prohibited from making a legitimate connection until the “dummy” connection is completed.

Ways to Protect Yourself Antivirus Software Antivirus Software Norton Norton McAfee McAfee Anti-Spyware Software Anti-Spyware Software Crap-Cleaner Crap-Cleaner Ad-Aware Ad-Aware SpyBot SpyBot

Firewalls Firewalls Some software firewalls may be enabled on your machine already. Some software firewalls may be enabled on your machine already. Windows XP uses one for example. Windows XP uses one for example. Routers Routers Better than the Windows firewall Better than the Windows firewall Does not interfere as much with useful programs Does not interfere as much with useful programs

Routers Cont’d Many routers have firewalls enabled on them. Many routers have firewalls enabled on them. Once you open a port for access to a program, you do not have to open it ever again, unlike Windows. Once you open a port for access to a program, you do not have to open it ever again, unlike Windows. Also function as small switches, which is beneficial to the home network. Also function as small switches, which is beneficial to the home network.

VPN’s Virtual Private Networks Virtual Private Networks Good for accessing a network remotely Good for accessing a network remotely Encrypts data so that unauthorized users can’t see the data being transferred. Encrypts data so that unauthorized users can’t see the data being transferred. Functions as a pipeline between your machine and the business network. Functions as a pipeline between your machine and the business network.

System Updates Updating your system and programs is critical. Updating your system and programs is critical. Security Fixes, Driver Updates, Etc… keep your system from being vulnerable after a vulnerability is discovered. Security Fixes, Driver Updates, Etc… keep your system from being vulnerable after a vulnerability is discovered. This is the end user’s responsibility. This is the end user’s responsibility.

Being Cautious is the best network defense. Being Cautious is the best network defense. Monitor your network usage, if you are an administrator. Monitor your network usage, if you are an administrator. Run antiviral and anti-spyware programs to keep your machines clean. Run antiviral and anti-spyware programs to keep your machines clean. If you don’t know what something does, don’t open it. If you don’t know what something does, don’t open it.