Information Security

1. Information Security

2. Risk Assessment • A thorough analysis of an organization’s vulnerability to security breaches and an identification of its potential losses. • A risk assessment should answer the following questions: • What resources or assets are at risk? • What methods could be taken to compromise those resources? • Who or what are the most likely threats to resources? • What is the probability that the organization or its resources will be compromised? • What are the consequences of those resources being compromised?

3. Risk Assessment

4. Security Policy Goals • Ensure that authorized users have appropriate access to the resources they need • Prevent unauthorized users from gaining access to facilities, cabling, devices, systems, programs, or data • Protect sensitive data from unauthorized access, from individuals both internal and external to the organization • Prevent accidental or intentional damage to hardware, facilities, or software • Create an environment in which the network and its connected nodes can withstand and, if necessary, quickly respond to and recover from any type of threat

5. Security Policy Content • What types of security policies should be defined: • Password policy • Software installation policy • Confidential and sensitive data policy • Network access policy • Telephone use policy • E-mail use policy • Internet use policy • Remote access policy • Cable Vault and Equipment room access policy.

6. Response Policy • Response Team roles: • Dispatcher: the person on call who first notices or is alerted to the problem. • Manager - The team member who coordinates the resources necessary to solve the problem. • Technical support specialists - The team members who strive to solve the problem as quickly as possible. • Public relations specialist - The team member who acts as official spokesperson for the organization to the public.

7. Common Security Risks Human Error, Ignorance, and Omission • These cause more than half of all security breaches sustained by voice and data networks. • Social engineeringstrategy - involves manipulating social relationships to gain access to restricted resources.

8. Human Error, Ignorance, and Omission • Risks include: • Intruders or attackers using social engineering or snooping to obtain user passwords. • Network administrators overlooking security flaws in network design, hard-ware configuration, operating systems, or applications. • Network administrators overlooking security flaws in network design, hard-ware configuration, operating systems, or applications. • An unused computer or terminal left logged on to the network, thereby providing an entry point for an intruder. • Users or administrators choosing easy-to-guess passwords.

9. Passwords Security • Guidelines for choosing passwords: • Always change system default passwords after installing new programs or equipment. • Do not use familiar information, such as your birth date, anniversary, pet’s name, child’s name, etc. • Do not use any word that might appear in a dictionary. • Make the password longer than six characters - the longer, the better. • Change your password at least every 60 days, or more frequently, if desired.

10. Physical Security • Locations on voice and data networks that warrant physical security: • Inside a central office : • Cable vaults • Equipment rooms • Power sources (for example, a room of batteries or a fuel tank) • Cable runs (ceiling and floor) • Work areas (anyplace where networked workstations and telephones are located)

11. Physical Security • Locations on voice and data networks that warrant physical security: • Outside telecommunications facilities: • Serving area interfaces and remote switching facilities • Exterior cross-connect boxes • Wires leading to or between telephone poles • Base stations and mobile telephone switching offices used with cellular telephone networks • Inside a business: • Entrance facilities • Equipment room (where servers, private switching systems, and connectivity devices are kept) • Telecommunications closet

12. Physical Security

13. Physical Security • Relevant questions: • Which rooms contain critical systems, transmission media, or data and need to be secured? • How and to what extent are authorized personnel granted entry? • Are authentication methods (such as ID badges) difficult to forge or circumvent? • Do supervisors or security personnel make periodic physical security checks? • What is the plan for documenting and responding to physical security breaches?

14. Remote Access • Modems are notorious for providing hackers with easy access to networks. • Although modem ports on connectivity devices can open access to significant parts of a network, the more common security risks relate to modems that users attach directly to their workstations. • When modems are attached directly to networked computers, they essentially provide a back door into the network. • War dialers - computer programs that dial multiple telephone numbers in rapid succession, attempting to access and receive a handshake response from a modem.

15. Encryption • The use of an algorithm to change data into a format that can be read only by reversing the algorithm. • Encryption ensures that: • Data can only be viewed and voice signals can only be heard by their intended recipient (or at their intended destination). • Data or voice information was not modified/altered after the sender transmitted it and before the receiver picked it up. • Data or voice signals received at their intended destination were truly issued by the stated sender and not forged by an intruder.

16. Key Encryption

17. Private Key Encryption

18. Public Key Encryption • Data is encrypted using two keys: One is a key known only to a user (a private key) and the other is a public key associated with the user. • Public-key server - a publicly accessible host (often, a server connected to the Internet) that freely provides a list of users’ public keys. • Key pair - The combination of the public key and private key . • Digital certificate - a password-protected and encrypted file that holds an individual’s identification information, including a public key.

19. Public Key Encryption

20. Encryption Methods • Kerberos - a cross-platform authentication protocol that uses key encryption to verify the identity of clients and to securely exchange information after a client logs on to a system. • PGP (Pretty Good Privacy) - a public key encryption system that can verify the authenticity of an e-mail sender and encrypt e-mail data in transmission. • IPSec (Internet Protocol Security) - defines encryption, authentication, and key management for TCP/IP transmissions.

21. Encryption Methods • SSL (Secure Sockets Layer) - a method of encrypting TCP/IP transmissions between a client and server using public key encryption technology. • When a Web page’s URL begins with the prefix HTTPS, it is requires its data be transferred from server to client and vice versa using SSL encryption. • Each time a client and server establish an SSL connection, they also establish a unique SSL session. • Handshake protocol - authenticates the client and server to each other and establishes terms for how they will securely exchange data.

22. Eavesdropping • The use of a transmission or recording device to capture conversations without the consent of the speakers. • Eavesdropping can be accomplished in one of four ways in wired circuits: • Bugging • Listening on one of the parties’ telephone extensions • Using an RF receiver to pick up inducted current near a telephone wire pair • Wiretapping, or the interception of a telephone conversation by accessing the telephone signal

23. Eavesdropping

24. Private Switch Security • A hacker might want to gain access to a PBX in order to: • Eavesdrop on telephone conversations, thus obtaining proprietary information • Use the PBX for making long-distance calls at the company’s expense, a practice known as toll fraud • Flood the PBX with such a high volume of signals that it cannot process valid calls, a practice known as a denial-of-service attack • Use the PBX as a connection to other parts of a telephone network, such as voice mail, ACD, or paging systems

25. Voice Mail Security • Voice mail - the service that allows callers to leave messages for later retrieval, is a popular access point for hackers. • If a hacker obtains access to a voice mail system’s administrator mailbox, they can set up additional mailboxes for private use. Valid voice mail users will never notice. • Privacy breaches - if a hacker guesses the password for a mailbox, they can listen to the messages in that user’s mailbox.

26. Telecommunications Firewall • A type of fire-wall that monitors incoming and outgoing voice traffic and selectively blocks telephone calls between different areas of a voice network. • Performs the following functions: • Prevents incoming calls from certain sources from reaching the PBX • Prevents certain types of outgoing calls from leaving the voice network • Can prevents all outgoing calls during specified time periods • Collects information about each incoming and outgoing call • Detects signals or calling patterns characteristic of intrusion attempts, immediately terminates the suspicious connection, and then alerts the system administrator of the potential breach

27. Telecommunications Firewall

28. Network Operating System • To begin planning client-server security, every network administrator should determine which resources on the server all users need to access. • Network administrators typically group users according to their security levels as this simplifies the process of granting users permissions to resources. • Attention is needed to ensure all security precautions are installed and monitoring the network operating system. • Updates and security patches to servers’ NOS software should be performed or monitored to ensure the highest level of security is currently implemented.

29. Network Operating System • Restrictions on network resources may include: • Time of day - Use of logon IDs can be valid only during specific hours, for example, between 8:00 A.M. and 5:00 P.M. • Total time logged in - Use of logon IDs may be restricted to a specific number of hours per day. • Source address - Use of logon IDs can be restricted to certain workstations or certain areas of the network • Unsuccessful logon attempts - As with PBX security, use of data network security allows administrators to block a connection after a certain number of unsuccessful logon attempts.

30. Firewall • Packet-filtering firewall - a device that operates at the Data Link and Transport layers of the OSI model.

31. Firewall • Traffic can be filtered based on criteria/policy: • Source and destination IP addresses • Source and destination ports • Use of the TCP, UDP, or ICMP transport protocols • A packet’s status as the first packet in a new data stream or a subsequent packet • A packet’s status as inbound or outbound to or from a private network

32. Firewall • Factors to be considered when choosing a firewall: • Does the firewall support encryption? • Does the firewall support user authentication? • Does the firewall allow the network administrator to manage it centrally and through a standard interface? • How easily can you establish rules for access to and from the firewall? • Does the firewall support filtering at the highest layers of the OSI model, not just at the Data Link and Transport layers?

33. Proxy Servers • Proxy server (Gateway) - a specialized network host that runs a proxy service (software). • Proxy servers manage security at all layer’s of the OSI model. • On a network, a proxy server is placed between the private and public parts of a network. • Proxy service - a software application on a network host that acts as an intermediary between the external and internal networks, screening all incoming and outgoing traffic.

34. Proxy Servers

35. Cellular Network Security • Hackers intent on obtaining private information can find ways to listen in on cellular conversations. • Potentially more damaging than eavesdropping is cellular telephone fraud. • cellular telephone cloning - occurs when a hacker obtains a cellular telephone’s electronic serial number (ESN), and then reprograms another handset to use that ESN. • To combat cloning fraud, cellular telephones that use CDMA and TDMA technology transmit their ESN numbers in encrypted form.

36. Wireless WAN Security • War driving - searching for unprotected wireless networks by driving around with a laptop configured to receive and capture wireless data transmissions. • Wired Equivalent Privacy (WEP) standard - a key encryption technique that assigns keys to wireless nodes. • Extensible Authentication Protocol (EAP) - defined by the IETF in RFC 2284. • Does not perform encryption. Instead, it is used with separate encryption and authentication schemes.