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Chapter 3 Security Basics. Jeremy Jordan. Who Should Make Information Security Policies?. Bottom-up approach – means the lower people make the security policies. This approach can be beneficial because the lower people know how to prevent attacks
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Chapter 3 Security Basics Jeremy Jordan
Who Should Make Information Security Policies? • Bottom-up approach – means the lower people make the security policies. • This approach can be beneficial because the lower people know how to prevent attacks • Top-down approach – means the higher people make the security policies. • This approach can be beneficial because the higher people know how the entire network works as a whole
Ways to Protect Systems • Layering • Limiting • Diversity • Obscurity • Simplicity
Network Password Access Control List Database Password Database Layering • Layering is the process of putting multiple different defenses in place to block attacks. • Passwords • Firewalls • Antivirus • This way if a attacker gets through one layer they still have to get through other layers.
Limiting • Limiting is based on using Access Control Lists to limit what users can do or access. • Access should be limited to the least amount necessary for the person to do their job.
Internet Internet Cisco Firewall Cisco Firewall CiscoFirewall WatchGuardFirewall Network Network Diversity • Diversity is related to layering. • Each layer needs to be different, so if an attacker gets through one layer they may not know how to get through the next. • Diversity can also be applied for the types for devices or applications used.
Obscurity • Don’t let attackers know information about your network. • Security policies • Equipment • Software • User passwords should be changed in an unpredictable way. • Users shouldn’t be able to change a password from Fluffy01 to Fluffy02.
Simplicity • Very complex networks can be difficult to manage • Networks should be simple from the inside but complex from the outside
Authentication • What you know • What you have • What you are
What You Know • Authentication that uses what a person knows • Passwords • PIN • Answer to personal question
What You Have • Authentication method based on what a person has. • Token • Smart Card • Proximity Card
What You Are • Authentication based on who the person is • Biometrics • Fingerprints • Face • Hand • Iris • Retina • Voice
Certificates • Certificates are used to bind a cryptographic key to a person who it is assigned to. • Then any encryption done with that key is from a known individual • Certificates issued by a Certification Authority (CA)
Kerberos • An authentication protocol developed by MIT • Used to verify the identity of network users • Is supported by: • Windows 2003 • Apple Mac OS • Linux
Challenge Response Approval or Denial CHAP • Challenge Handshake Authentication Protocol • Allows a server to verify a computers identity • Server can start a CHAP challenge at any time the connection is open
Server authenticates client Client authenticates server Mutual Authentication • A two-way authentication method • Server can authenticate the Client • Client can authenticate the server • Used to defend against identity attacks
Multifactor Authentication • This is just using two or more authentication methods to verify a user. • Password and token • Fingerprint and password • Fingerprint and smart card
Controlling Access To The Computer • Access Control Lists (ACLs) are used to control what a user who has accessed a system can and can’t do. • ACLs are stored in Access Control Entries (ACE) • Users in a group inherit all ACL permissions applied to the group
Access Control Models • Mandatory Access Control (MAC) • A user is not allowed to give other users access to a file/folder • All permissions are set, and can only be changed, by the administrator • Role Based Access Control (RBAC) • Allows for permissions to be given to a specific role • Users are assigned to a role and inherit it’s permissions
Access Control Models • Discretionary Access Control (DAC) • The least restrictive model • A user can change other users permissions of files/folders
Auditing Information Security • Auditing is performed to ensure that the proper security controls are in place • Auditing can be done in two ways • Logging • Logs Keep records that show what users are doing and when • System Scanning • Scans users permissions to see if they are different then what they should be.