Data integrity characteristic: authenticity

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Data is authentic when it genuinely comes from the source it claims.

A False

B True

2. An email says it is from the ATO, but the sender address was faked to look like the ATO. Which describes this data?

A Not authentic: the source is spoofed

B Authentic: it names a trusted source

3. Which step best verifies the origin of a file?

A Check its digital signature against the sender's public key

B Check that the file name looks professional

4. A data set is accurate, so it must also be authentic.

A True

B False

5. Which is an example of forged data?

A A fake invoice made to look like it came from a real supplier

B A real invoice with a typing error in the total

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Authenticity		AData that looks correct may still be forged. Authenticity needs the origin to be verified, not just the appearance checked.
2Spoofed sender address		BData is authentic when it genuinely comes from the source it claims and has not been forged or spoofed.
3Verifying the origin of a file by checking it was signed by the trusted sender		CIF source IN trusted_sources THEN accept ELSE reject
4Only accepting data from a trusted source on an approved list		DForged data that pretends to come from a trusted source, so it is not authentic.
5IF data looks correct THEN trust it		EA sender name can be spoofed. Trusting the name alone does not verify that the data genuinely came from the source.
6IF sender_name = "Payroll Team" THEN accept		Fverify_signature(file, sender_public_key)

Definitions

Authenticity

Fill in the Blanks

Complete each line of code by filling in the missing parts.

IF sender = trustedSource ____ accept(data)

IF NOT sigValid THEN ______(data)

IF sender __ trustedSource THEN flag(data)

valid _ verifySignature(data, sig)

IF domainOk ___ sigValid THEN accept(data)

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A trusted = ["HR", "Anonymous"]

B source = "HR"

C if source in trusted:

D print("Authentic")

Question 2

A sender = "bank.com.au"

B real = "bank.com.au"

C if sender != real:

D print("Origin verified")

Question 3

A ok = check_size(file)

B if ok:

C print("Authentic")

Question 4

A email = get_email()

B domain = email.domain

C if domain in trusted:

D reject(email)

E else:

F quarantine(email)

Question 5

A if sender_verified:

B trust = "high"

C else:

D trust = "high"

Answer Key

Data integrity characteristic: authenticity

Section A: Quick Questions

B — True

A — Not authentic: the source is spoofed

A — Check its digital signature against the sender's public key

B — False

A — A fake invoice made to look like it came from a real supplier

Section B: Match the Pairs

Authenticity → Data is authentic when it genuinely comes from the source it claims and has not been forged or spoofed.

Spoofed sender address → Forged data that pretends to come from a trusted source, so it is not authentic.

Verifying the origin of a file by checking it was signed by the trusted sender → verify_signature(file, sender_public_key)

Only accepting data from a trusted source on an approved list → IF source IN trusted_sources THEN accept ELSE reject

IF data looks correct THEN trust it → Data that looks correct may still be forged. Authenticity needs the origin to be verified, not just the appearance checked.

IF sender_name = "Payroll Team" THEN accept → A sender name can be spoofed. Trusting the name alone does not verify that the data genuinely came from the source.

Section C: Definitions

Authenticity — Data is authentic when it genuinely comes from the source it claims and has not been forged or spoofed. Verifying its origin shows it can be trusted.

Section D: Fill in the Blanks

IF sender = trustedSource THEN accept(data)

IF NOT sigValid THEN reject(data)

IF sender != trustedSource THEN flag(data)

valid ← verifySignature(data, sig)

IF domainOk AND sigValid THEN accept(data)

Section E: Spot the Error

A — The trusted list must only hold verified sources. An anonymous source can't be verified, so data from it can't be treated as authentic. Line 1 should list only trusted sources such as "HR" and "Payroll".

C — Origin is verified when the sender matches the real source. Using != would call mismatched (possibly spoofed) senders verified. It should be if sender == real:.

A — Authenticity depends on verifying where the data came from. Checking file size says nothing about the origin and can't detect a forged file. It should be ok = check_signature(file).

D — Data from a trusted source is treated as authentic and should be accepted. Rejecting it throws away genuine data. Line 4 should be accept(email), and untrusted email goes to quarantine.

D — If the sender is not verified, the data may be forged or spoofed, so trust should be low. Giving unverified data high trust defeats authenticity. Line 4 should be trust = "low".