Network Security

Classification in the OSI reference model SSL/TLS history TLS security services and protocol architecture Classification in the SI reference odel SSL/TLS history TLS security services and protocol architecture Overview Network Security, WS 2008/09, Chapter 9 4 Classification in the OSI Reference Model (1) The transport layer provides communication between application processes (instead of communication between end-systems) Its main tasks are: Isolation of higher protocol layers from the technology, structure and deficiencies of deployed communications technology Transparent transmission of user data Global addressing of application processes, independently of lower layer addresses (Ethernet addresses, telephone numbers, etc.) Overall goal: provision of a (if required reliable) end-to-end service. Network Security, WS 2008/09, Chapter 9 5 Classification in the OSI Reference Model (2) Transport layer security protocols enhance the transport layer service by assuring additional security properties. As they usually require and are built upon a transport service, they actually represent session layer protocols according to the terminology of the Open Systems Interconnection (OSI) reference model. However, based on the Internet terminology where the application layer is directly on top of the transport layer, we use the term transport layer security protocols. Network Security, WS 2008/09, Chapter 9 6 Classification in the OSI reference model SSL/TLS history TLS security services and protocol architecture Classification in the OSI reference model SSL/TLS history TLS security services and protocol architectur