How many QCAA Digital Solutions questions cover Interactions between users, data and digital systems?

Q: How many QCAA Digital Solutions questions cover Interactions between users, data and digital systems?

AusGrader has 19 QCAA Digital Solutions questions on Interactions between users, data and digital systems, all with instant AI grading and detailed marking feedback.

QCAA (QCE) Digital Solutions — Interactions between users, data and digital systems Questions & Answers | AusGrader

Q1

2024

QCAA

1 mark

Q1

1 mark

Which element of visual communication, if not used appropriately, could risk the accessibility of a digital system?

A

line

B

form

C

scale

D

shape

Q9

2025

QCAA

1 mark

Q9

1 mark

Which component of a digital solution is required for efficient data processing?

A

secure login and authentication processes

B

visually appealing interface design

C

maintainable programming

D

scalable database design

Q14

2020

QCAA

21 marks

Q14

Two novice programmers who live in different locations want to develop a method for securing their email communication. They have decided to:

meet in the same location
use a generic code library that contains functions relating to a set of cryptology algorithms called ‘Blowfish’
use only UTF-8 data encoding, e.g. the character ‘%’ is considered to have a length of 8 bits in total
create their own programs using different languages
generate encrypted text using their programs
copy and paste encrypted text into their emails.

Function name	Blowfish key expansion	Blowfish crypt
Function code	`BlowfishInitiate(key)`	`Blowfish(Value, KeySet, Process-Type)`
Purpose	Completes the initial key expansion processes. Returns a data structure called `Blowfish KeySets`.	Completes the block algorithm process for encryption or decryption. Accepts a 64-bit–length set of values in the form of text, along with the pre-processed `Blowfish KeySets`.
Inputs	Key: text-based, 64-bit in length	Value: text-based, 64-bit in length KeySet: returned data structure from the `BlowfishInitiate` function Process-Type: 1 for encrypt, 2 for decrypt
Returns	KeySet	Text-based value
Example	`BlowfishInitiate("J$8%*$#d")`	`Blowfish("abcdefg",MyKeySet,1)`

Note: If any input does not meet a function’s length requirements, the function will fail and potentially cause a runtime error.

Q14a

6 marks

Symbolise an algorithm that the programmers could use to encrypt their Unicode set of text. The algorithm should use the function library calls in the table as required.

BEGIN
    INPUT key;

    IF key contains letter characters AND
       Length of key = 8 THEN

        MyKeySet = Blowfish_Initiate(key)

        INPUT user_text
        SET cipher_text = ""

        IF Length of user_text >= 8 THEN

            IF Length of user_text MOD 8 > 0 THEN
                FOR index = 1 TO Length of user_text MOD 8
                    user_text = user_text + " "
                NEXT index
            ENDIF

            FOR EACH set of 8 character BlockSet in user_text
                cipher_text = Blowfish(BlockSet, MyKeySet, 1)
            ENDFOR

            OUTPUT cipher_text

        ENDIF
    ENDIF

END

Marking Criteria

Descriptor	Marks
Solves the problem without errors	6
Could have solved the problem except for 1 logic error OR could have solved the problem except for syntax errors	5
Could have solved the problem except for 2 logic errors OR could have solved the problem except for 1 logic error and syntax errors	4
Could have solved the problem except for 3 logic errors OR could have solved the problem except for 2 logic errors and syntax errors	3
Could have solved the problem except for 4 logic errors OR could have solved the problem except for 3 logic errors and syntax errors	2
Could have solved the problem except for 5 logic errors OR could have solved the problem except for 4 logic errors and syntax errors	1
Does not satisfy any of the descriptors above.	0

Q14b

6 marks

The programmers make the solution publicly available on their website as a web application. Explain and justify how they could implement two useability principles to optimise user experience.

An important usability principle is utility. The web app user interface should be responsive as it needs to adjust to all viewport sizes (display device). As users will use various devices, such as mobile phones and laptops, to access the app, the solution needs to adjust appropriately to ensure it is practical and accessible. Responsiveness can be implemented by using breakpoints and a grid for the layout of interface elements.

The solution also needs to be accessible. It should use suitable colours and font (typeface, size and style) to ensure it is accessible to all users, regardless of visual or physical disability. Accessibility can be implemented by checking the colours and fonts with an accessibility checker, available online, to ensure they meet accessibility standards.

Marking Criteria

First Usability Principle

Descriptor	Marks
States a relevant useability principle	1
Describes the useability principle in relation to the solution	1
Justifies how to implement the useability principle	1

Second Usability Principle

Descriptor	Marks
States a relevant useability principle	1
Describes the useability principle in relation to the solution	1
Justifies how to implement the useability principle	1

Q14c

9 marks

Evaluate whether the programmers have developed the most secure method to encrypt an email message by identifying two strengths and two weaknesses in the steps. Support all statements with examples. Provide two recommendations and justify how each recommendation would improve security.

The method used is relatively secure as Blowfish is a well-known and trusted method of encryption. The method could be made more secure with some recommendations to improve security.

The strength of meeting in the same location is that they reduce the risk of a security breach by not using technology that could be digitally intercepted. The weakness is that someone could overhear their conversation — this depends on the security of the location.

The strength of using different languages is that if one program is breached, it is contained, because the same method of breaching may not work for a program written in another language. A weakness may be the language used, as different languages have different levels of vulnerability.

To improve security, it would be recommended to test the program that is written before using it to identify any issues prior to implementation. Another recommendation would be to consider the vulnerabilities of the range of programming languages and use the least vulnerable languages to optimise security.

Marking Criteria

Conclusion

Descriptor	Marks
Provides a valid conclusion about Blowfish	1

Evaluation

Descriptor	Marks
States a valid weakness	1
States a second valid weakness	1
States a valid strength	1
States a second valid strength	1

Improving Security

Descriptor	Marks
Provides a relevant recommendation	1
Justifies the provided recommendation	1
Provides a second relevant recommendation	1
Justifies the second provided recommendation	1

Q2

2023

QCAA

1 mark

Q2

1 mark

Screen-based user interfaces must dynamically adjust for different screen sizes because devices such as mobile phones and televisions have different aspect ratios and dimensions.

Which useability principle does this demonstrate?

A

utility

B

safety

C

validity

D

reliability

Q3

2023

QCAA

1 mark

Q3

1 mark

Arranging and organising the UI elements of a user interface demonstrates use of

A

useability and accessibility.

B

elements of visual communication.

C

principles of visual communication.

D

a suitable programming environment.

QCAA Digital Solutions Interactions between users, data and digital systems

First Usability Principle

Second Usability Principle

Conclusion

Evaluation

Improving Security

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