UNIT 4 - DIGITAL IMPACTS - Subject Matter

In Unit 4, students learn how data is shared in both local and global contexts, particularly how digital solutions are increasingly required to exchange data securely and efficiently. Students will understand elements of cybersecurity by exploring the conditions, environment and methods for enabling data to flow between different digital systems. They will analyse data privacy and data integrity risks associated with transferring data between applications and evaluate the personal, social and economic impacts associated with the use and availability of both public and private data. Students will develop an application that simulates the exchange of data between two applications.

Unit requirements
In Unit 4, the programming language must allow the following operations:

Students may use an object-oriented programming language.

SQL syntax version must be based on generic ANSI-style SQL, i.e. SQL-92.


Unit Objectives

Unit objectives are drawn from the syllabus objectives and are contextualised for the subject matter and requirements of the unit. Each unit objective must be assessed at least once.
Note (*) Items to be assessed in IA3 but NOT EA

Students will:

  1. recognise and describe programming elements, components of data exchange systems, privacy principles and data exchange processes
  2. symbolise and explain data structures and specifications, methods for exchanging data, algorithms and data-flow relationships within and between systems
  3. analyse problems and information related to digital systems
  4. determine solution requirements and prescribed and self-determined criteria*
  5. synthesise information and ideas to determine possible components of digital solutions
  6. generate components of the digital solution*
  7. evaluate impacts, components and solutions against prescribed and self-determined criteria to make refinements and justified recommendations
  8. make decisions about and use mode-appropriate features, language and conventions for particular purposes and contexts.*


Subject Matter:

Note, subject matter has been identified (1.c.2, 2.b.1 etc for ease of reference)


Topic1: Digital Methods for exchanging data

In this topic, students will:

  1. recognise and describe
    1. encryption and authentication strategies appropriate for securing data transmissions and their differences
    2. features of symmetric (Data Encryption Standard — DES, Triple DES, AES — Advanced Encryption Standard, Blowfish and Twofish) and assymetric (RSA) encryption algorithms
    3. how data compression, encryption and hashing are used in the storage and transfer of data
    4. how simple algorithms consist of input, process and output at various stages
    5. how useability principles are used to inform solution development
    6. how the elements and principles of visual communication inform user interface development
  2. explain
    1. Australian Privacy Principles (2014) and ethics applicable to the use of personally identifiable or sensitive data from a digital systems perspective
    2. network transmission principles, including latency, jitter, guarantee and timeliness of delivery, and protocols relevant to the transmission of data over the internet, e.g. HTTP, HTTPS, FTP, VPN, streaming and broadcasting data packets
    3. methods for data exchange used to transfer data across networked systems including REST, JSON and XML
  3. symbolise, analyse and evaluate Caesar, Polyalphabetic (e.g. Vigenere and Gronsfield), and one-time pad encryption algorithms
  4. describe data using appropriate naming conventions, data formats and structures
  5. symbolise and explain
    1. how application sub-systems, e.g. front end, back end, work together to constitute a solution
    2. secure data transmission techniques and processes, including the use of encryption, decryption, authentication, hashing and checksums
    3. the basic constructs of an algorithm, including assignment, sequence, selection, condition, iteration and modularisation
  6. symbolise
    1. representations of a digital solution
    2. data flow through a system using data flow diagrams.



Topic 2: Complex digital data exchange problems and solution requirements

In this topic, students will:

  1. analyse problems and information to determine
    1. boundary of scope of given problems
    2. constraints and limitations of environments
    3. requirements of the solution components
    4. necessary coded modularity and features
    5. factors and risks that affect data security, including confidentiality, integrity and availability, and privacy
    6. existing code within inbuilt libraries
    7. prescribed and self-determined criteria to appraise the implementation, e.g. protection, security and interactions
  2. analyse, evaluate and make refinements to data to ensure completeness, consistency and integrity
  3. analyse and explain a system’s data process by developing data flow diagrams that link external entities, data sources, processes and data storage
  4. determine manageable aspects of a problem through a decomposition and analysis of
    1. constraints
    2. risks
    3. available tools and code libraries
    4. data storage and output requirements
    5. data interface
  5. determine data sources required to generate data components
  6. symbolise algorithmic steps as pseudocode
  7. explain the purpose of code and/or algorithm statements using code comments and annotations
  8. communicate using
    1. digital technologies–specific language
    2. language conventions; textual features such as annotations, paragraphs and sentences; and referencing conventions to convey information to particular audiences about digital solutions
    3. sketches or diagrams to present information and ideas about the problem and programmed digital solutions
    4. the modes of visual, written and spoken communication to present data and information about digital solutions.



Topic 3: Prototype digital data exchanges

In this topic, students will:

  1. Synthesise information and ideas to determine prototype components of data exchange solutions
  2. use a suitable programming environment to
    1. implement algorithms using modularisation
    2. receive data from an external source, and process and display the data in an appropriate format
    3. incorporate existing code libraries (where applicable)
  3. develop simple Caesar, Polyaphabetic (e.g. Vignere and Gronsfeld), and one-time pad encryption algorithms
  4. generate
    1. a well-ordered and unambiguous algorithm to solve defined problems using pseudocode
    2. a prototype digital solution that uses appropriate data structures including JSON or XML, to exchange data
  5. manipulate data from an external source
  6. generate data structures using
    1. SQL CREATE, DROP and ALTER statements
    3. SQL SELECT query, including WHERE, GROUP BY, HAVING, ORDER BY, sub-selection and inner-joins clauses
  7. generate within programmed methods
    1. sequence
    2. selection, i.e. use of single and nested, simple or compound conditions
    3. iterations, including nesting or simple or compound conditions
    4. use of code-specific arithmetic comparison and logical operators, including real division, integer division, modulus
    5. use of data types, error-checking functions and conversions
    6. use of structures, including one-dimensional collections, e.g. arrays and lists
  8. evaluate by desk checking algorithms to predict the output for a given input, identify errors and validate algorithms
  9. evaluate
    1. security impacts of data and its use, dissemination, storage, accuracy and ownership on personal, social and economic needs
    2. the solution against prescribed and self-determined criteria
    3. solutions by testing to refine their accuracy, reliability, maintainability, efficiency, effectiveness and useability
    4. and make justified recommendations related to the security impacts of digital solutions, taking into consideration changes in interactivity and ways information and data are created, used and shared.