In this tutorial we will consider abstract non-interference as a formal model for reasoning about language based security. Abstract non-interference generalises standard non-interference by modelling the information leaked as abstract properties of concrete computations. In this case abstractions model both the observational capabilities of attackers and the amount of information that may flow between program components, e.g., from private to public variables, dynamically at run-time. We prove that abstract non-interference generalizes known models of attackers in language-based security and provides at the same time a formal setting for comparing many of the known approaches for weakening non-interference. We introduce a proof system for checking abstract non-interference and systematic methods, i.e., abstraction transformers, for deriving the most concrete harmless attacker for which a program is secure together with the corresponding maximal amount of information released. This provides the possibility of associating programs with canonical attackers and compare them according to their relative degree of security in the lattice of abstract interpretations. Due to its semantic-based approach and the generality of abstract interpretation and non-interference notions, abstract non-interference can be fairly considered as a unifying theory for understanding and reasoning about information-flow in programming languages, including security, program slicing and dependence analysis as special cases.

Part 1 - The Changing Telecom Service Environment: Understanding the buzzwords NGN, SDP, SOA and Web 2.0
Next Generation Networks (NGNs) are representing an important milestone in the evolution of fixed and mobile telecommunication networks towards an all-IP based multimedia services network environment. Positioned in the centre of the convergence of telecommunications and the internet, a major question arising is how will the new value chain of converged networks look like and what kind of future multimedia killer applications will justify the huge investments to be undertaken for NGN introduction. Based on the success of the internet under the banner of Web 2.0 the hard lesson learned by the telecoms industry is, that there won´t be any single killer application in the future but rather a multitude of the niche services have to provided to a broadening spectrum of user groups, also called communities. This will lead to a three layer architecture, namely the separation of networks, service platforms and applications, in which the later will be increasingly provided by third parties.
The notion of Service Delivery Platforms (SDPs) is today used to describe the functions needed to create, deploy, provision and execute services on top of various network types, including legacy networks and emerging NGN infrastructures. Efficiency in this context is enabled by the concept of reusable service components designed independently of underlying network technologies, which brings us to the notion of Service oriented Architectures (SOA) considered today as holy grail for future proof system design.
This part of the tutorial introduces the main buzzwords of converging networks and puts them into context by outlining a target SOA Telcom architecture, which is forming the base of the FOKUS Open SOA Telco playground, an extensible technology testbed for prototyping innovative multimedia applications on top of converging networks.

Part 2: Service Engineering and Service Quality Aspects
In the context of the dynamic and expanding field described in Part 1, the challenge for the integration and convergence of the media is to design and implement an environment for the creation of advanced telecommunication services (Next Generation Network Services). This should happen on the basis of a library of basic service components, and it should provide engineering and quality assurance means that go well beyond standard 'clipboard-architectures' with some testing support.
Our approach introduces a declarative specification layer, which is used for the construction of the desired services according to {\em global constraints} that guarantee executability and other consistency conditions. These constraints are the basis for an on-line verification via model checking during the interactive service design process.
Important for the success of the method is the high performance and the availability of diagnostic information in the case of failure: Several hundred constraints must be checked in real-time, and the diagnostic information must reflect the responsible constraint violation as concisely as possible, while preserving as much of the structure of the developed service as possible.