The University of Sheffield
Department of Computer Science

COM3008 Systems Design and Security

Summary This module provides a grounding in software systems design, highlighting security issues. Topics include: choice of software lifecycle, customer-developer interaction, requirements capture, information management, database design, functional design, design patterns, software architectures, user interfaces, data validation, software verification and testing. Security topics include: threats, countermeasures, policies and technologies. The lectures are complemented by an integrating team-project. This 20-credit unit prepares students to participate in the Software Hut (COM3420) in the Spring.
Session Autumn 2024/25
Credits 20
Assessment
  • Coursework (team project and individual test report) and formal examination
Lecturer(s) Dr Emma Norling
Resources
Aims

This unit aims to:

  • Develop customer-oriented interaction, and software analysis and design skills to create robust software systems for target customers;
  • Promote an awareness of common cyber threats and the security policies and design strategies that reduce risk;
  • Develop group-working skills and technical software development skills in building a software system with a layered architecture.
Learning Outcomes 

By the end of the module the student will be able to:

  • Justify the application of suitable customer interaction, risk management and development strategies for different kinds of software system.
  • Create structured designs capturing the data, process and time views of a software system that accurately model the semantics of the requirements.
  • Apply design patterns to maximise cohesion and minimise coupling within an object-oriented software system.
  • Mitigate privilege escalation and injection attacks through suitable methods for authorisation, authentication, data integrity, and confidentiality.
  • Understand relational algebra and apply the Boyce-Codd-Fagin normal forms, and the entity-relationship approach for normalising databases.
  • Work cooperatively in a team to analyse realistic business requirements of a target customer and deliver a software system.
  • Design, build and test a secure information system with a three-layer architecture, integrating a user interface, business logic and a SQL database.
Content
  • Software Engineering – problems, solutions, lifecycles; how to pick an approach
  • Information Security – vulnerabilities, threats, countermeasures, policies, legal obligations
  • Project Management – people, product, process; developer-client psychology, conceptual bias
  • Requirements Modelling – UML Use Case Diagram; requirements gathering techniques
  • Requirements Case Study – interactive role-playing adventure-game exercise for customer/developer pairs
  • Information Modelling – building a data dictionary, UML Class Diagram; atomicity/dependency, semantic relation
  • Database Design – entity relationship modelling, data normalisation to 3NF/4NF, traditional vs ERM approach
  • Query Processing – from Relational Algebra to SQL; query optimisation
  • Java and Databases – Java Database Connectivity API, MySQL server, SQL injection, data validation
  • Security and Robustness – authentication, authorisation, confidentiality, integrity, non-repudiation; distribution, penetration, concurrency
  • Encryption – digital fingerprints and certificates, symmetric key, public/private key, Java security API
  • Control/Data Flow Modelling – UML Activity Diagram; sequence, selection, iteration, composition; swim lanes, object flow
  • State-Based Modelling – UML State Machine Diagram; reactive systems, behaviour vs protocol models
  • Design Patterns – Command, State, Mediator, Template Method, Chain of Responsibility, Composite, Abstract Factory, Bridge
  • User Interface Design – State machines applied to screen modes and transitions, Java Swing composite design patterns
  • Architectural Design – UML deployment and package diagrams; layered, pipelined and transform-centre architectures
  • Formal Systems Design – UML Object Constraint Language, adding first-order logic to UML diagrams
  • Verification and Testing – formal and informal methods to ensure correctness, test coverage
  • Agile Methods – DSDM, Scrum, eXtreme Programming; putting agile principles to work
Restriction This module cannot be taken with COM2008.
Teaching Method
  • Lecture classes convey basic concepts (Objectives 1-4).
  • Interactive sessions develop interviewing, analysis and design skills (Objectives 1-4).
  • Team project develops group working and systems development skills (Objectives 5-6)
Feedback Formative test on Blackboard to prepare for the exam. Projects marked using published criteria, feedback sheets returned within 3 weeks.