Information Security

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Information Security
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Risk Assessment

• A thorough analysis of an organizations
  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?

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Risk Assessment
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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

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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.

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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.

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Common Security Risks

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

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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.

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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, pets name, childs
  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.

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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)

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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

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Physical Security
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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?

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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.

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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.

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Key Encryption
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Private Key Encryption
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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 individuals
  identification information, including a public
  key.

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Public Key Encryption
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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.

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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 pages 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.

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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

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Eavesdropping
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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
  companys 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

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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
  systems 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 users mailbox.

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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

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Telecommunications Firewall
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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.

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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 800
  A.M. and 500 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.

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Firewall

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

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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 packets status as the first packet in a new
  data stream or a subsequent packet
• A packets status as inbound or outbound to or
  from a private network

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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?

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Proxy Servers

• Proxy server (Gateway) - a specialized network
  host that runs a proxy service (software).
• Proxy servers manage security at all layers 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.

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Proxy Servers
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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 telephones 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.

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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.