U1. Security Services

U1. Security Services

1. Entity Authentication

   • Provides confirmation to one entity that another entity is who they say they are at a specific point in time
   • Only provides confidence at the time of usage
   • Addresses Maquerade threat
   • Typically used at the start of a connection but could be used at any point

2. Origin Authentication

   • Provides a check on the source of information
     • Authentication allows a check to be made to say if data really did come from a specific user
   • Does not provide protection against info being duplicated or modified
   • Protects against integrity violation Threat

3. Access Control

   • Protects against the unauthorised use of resources
     • Use of a communications resource
     • reading, writing, deletion of information, exececution of a processing resource
   • Protects against fundamental threats of integrity violation, information leakage, illegitimate use

4. Data Confidentiality

   • Protection against unauthorised disclosure of information
     • 4 Types
       • Connection Conf
         • Conf for all data on a given connection
       • Connectionless Conf
         • Provides conf in a packet or single connectionless data unit
       • Selective Field Conf
         • Conf of selected fields within user data.
       • Traffic Flow Conf
         • Prevent confidential data leaking from a traffic flow

5. Non Repudiation

   • Protection against a sender denying they sent or received information
     • Non-repudiation of origin = Provides protection against a sender of data denying that data was sent.
     • Non-repudiation of delivery Protects against the receiver denying that the data was received

6. Data Integrity

   • Active Threats to validity of data
     • 5 Types of Integrity Service
       • Selective field connectionless integrity
         • provides for the integrity of selective fields within a single connectionless data unit.
       • Selective field connection integrity
         • integrity of selected fields within the user data of a data unit
       • 1. Connection integrity with recovery
         • Provides integrity on all data on a connection. Detects modification, deletion or replay. Can also attempty recovery if a violation is detected
       • Connection integrity without recovery
         • Same as 1. just no recovery
       • Connectionless integrity
         • provides integrity assurance to the recipient, enabled to determine if data unit has been modified. a limited form of replay detection may be provided.