How many QCAA Digital Solutions questions cover Digital methods for exchanging data?

AusGrader has 49 QCAA Digital Solutions questions on Digital methods for exchanging data, all with instant AI grading and detailed marking feedback.

QCAA (QCE) Digital Solutions — Digital methods for exchanging data 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

Q1

2020

QCAA

1 mark

Q1

1 mark

Asymmetric encryption algorithms

A

all use one key.

B

only use private keys.

C

have a block size of 64.

D

use different keys for encryption and decryption.

Q13

2021

QCAA

5 marks

Q13

In an online silent auction, items are posted on a public website and participants post a secret bid on the items they would like to purchase. Bidders cannot see each other’s bids. The bidding period is 7 consecutive days.
At the end of the auction, all bid values are revealed on the website and the highest bidder pays the amount they posted to obtain the item.

Q13a

3 marks

Explain how checksums, encryption and authentication would improve the security of the data exchange in this scenario.

A checksum algorithm would be used to inspect the binary representation of auction data. If the checksum from the user is different from the checksum on the server, it means that the data has been corrupted or manipulated.

Encryption would be used to scramble the auction data to make it impossible to read in transit, but allowing it to be decrypted by the authorised recipient with a secret key.

Authentication would be used to verify the identity of the participant by using a digital signature or authentication code. A digital signature confirms that the bidder is who they say they are.

Marking Criteria

Descriptor	Marks
Explains how the security of the data exchange would be improved through checksums	1
Explains how the security of the data exchange would be improved through encryption	1
Explains how the security of the data exchange would be improved through authentication	1

Q13b

2 marks

Recommend one encryption method to securely store auction data and justify your response.

I would recommend AES for encrypting auction data to avoid a security breach. AES supersedes DES and 3DES and uses 128-bit blocks with 128, 192 and 256-bit encryption keys, whereas DES and 3DES use 64-bit blocks and key encryption. DES and 3DES are older ciphers and easily cracked in as little as one day, which would provide an opportunity for a hacker to gain access to auction data before the bids are revealed.

Marking Criteria

Descriptor	Marks
Recommends a valid encryption method	1
Effectively justifies the recommended encryption method	1

Q11

2022

QCAA

2 marks

Q11

2 marks

Explain the features of two network transmission protocols for transferring data between websites.

Two network transmission protocols are HTTP and HTTPS.
HTTP (hypertext transfer protocol) transfers data as text and offers no encryption and no authentication. This can be intercepted so should not be used for transferring data between websites.
In contrast, HTTPS (HTTP secure) uses a range of encryption protocols, e.g. TLS standard and certificates to confirm the identity of the server, making it the more secure option.

Marking Criteria

Descriptor	Marks
Explains features of one valid network transmission protocol	1
Explains features of another valid network transmission protocol	1

Q12

2021

QCAA

18 marks

Q12

A mobile application (app) allows car owners to remotely unlock their cars if they lock the keys inside or their keys malfunction. Once users have created an account, they can request a remote unlock by entering their username and password.

The user data that is required to set up an account includes:

full name
date of birth
home address
driver licence number
vehicle make, model and colour
vehicle registration.

Q12a

6 marks

Analyse the information and evaluate risks to data confidentiality, integrity and availability for this app. Justify your response with three examples.

A data confidentiality risk is the possibility that an unauthorised person could observe the user data in transit. For example, the app requires a password for the user to log in and the data would need to be encrypted so that it cannot be stolen.

A data integrity risk is the possibility that the data could become corrupted, lost or be maliciously manipulated. For example, the wrong car might be unlocked or a hacker might use the data to cause distress.

A data availability risk is the possibility that someone may interfere with transmission to prevent data packets from reaching the intended destination, allowing them to access the person's car so that they can steal it.

Marking Criteria

Descriptor	Marks
Logically evaluates risks to data: confidentiality	1
Logically evaluates risks to data: integrity	1
Logically evaluates risks to data: availability	1
Justifies this evaluation by providing a coherent example of a risk to data: confidentiality	1
Justifies this evaluation by providing a coherent example of a risk to data: integrity	1
Justifies this evaluation by providing a coherent example of a risk to data: availability	1

Q12b

2 marks

Identify a relevant Australian Privacy Principle and explain an ethical consideration when using app data.

Australian Privacy Principle: Security of personal information. Allow an administrator to de-identify or destroy personal information once it is no longer in use.

Ethical consideration: Security of personal information is important if the user sells their car, or if the car is no longer in use. The user should not be getting unnecessary calls or marketing materials for a service they no longer use or for a car they no longer own, and it would be unsafe for the original owner to still have access to the vehicle once it has been sold.

Marking Criteria

Descriptor	Marks
Identifies a relevant Australian Privacy Principle (APP)	1
Logically explains an ethical consideration relating to the identified APP	1

Q12c

2 marks

You discover that the app uses a Caesar cipher to encrypt data, allowing you to intercept a password in transit. Perform a desk check for five iterations to decrypt the password ‘KYIWW’.

ABC DE FG H I J K L M N O P Q R S T U V W X Y Z

KEY SHIFT	PASSWORD
0	K Y I W W
1	J X H V V
2	I W G U U
3	H V F T T
4	G U E S S

Marking Criteria

Descriptor	Marks
Performs a desk check that decrypts the password using iterations	1
Contains no errors	1

Q12d

8 marks

A friend is interested in learning more about encryption. Use pseudocode to symbolise a simple Caesar cipher as a demonstration.

BEGIN
INPUT string plainText
INPUT int keyShift
SET string alphabet =ABCDEFGHIJKLMNOPQRSTUVWXYZ
SET encryptedText = ""
    FOR each character in plainText
        SHIFT character by keyShift
        APPEND letter to encryptedText
    END FOR
    RETURN encryptedText
END

Marking Criteria

Descriptor	Marks
Symbolises INPUT for password string	1
Symbolises INPUT for key or shift integer	1
Symbolises declarative statement for alphabet	1
Symbolises a FOR loop to traverse password one character at a time	1
Symbolises a function to encrypt password one character at a time, using the key	1
Symbolises RETURN for encrypted password	1
Symbolises an algorithm with no logic errors	1
Effectively uses pseudocode conventions	1

QCAA Digital Solutions Digital methods for exchanging data

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