A2 Data Security & Integrity Processes

Question 1

Cryptography

Answer 1

Protecting data by converting plaintext –> ciphertext so that it cannot be understood without the correct key.

Keep data secure when it is sent over a network.
To prevent unauthorised access, data theft, or modification.
To maintain the three principles of security: Confidentiality, Integrity, Authentication. Cryptography converts readable plaintext into unreadable ciphertext. This allows secure communication even if attackers intercept the data.

Question 2

File Encryption

Answer 2

Encryption is the process of converting data into an unreadable format using a mathematical algorithm and a key. Only someone with the correct decryption key can revert the ciphertext to its original form.
Symmetric encryption: Same key is used for both encryption and decryption.
Asymmetric encryption: Uses a public key to encrypt and a private key to decrypt.

Question 3

Caesar Cypher

Answer 3

Caesar Cypher replaces each letter of the alphabet with another letter a fixed distance away from the original letter. To decrypt the message, recipient must know how many places the alphabest has been shifted by, this is known as the key. If the recipient knows the key, they can decrypt the message.

Question 4

Vernam Cypher

Answer 4

Vernam Cypher offers perfect security if the encryption key is equal to or longer than the plaintext message, if the key is truly random and if the key is used only once and then destroyed.

Question 5

Biometrics

Answer 5

Measurement and recording of physical characteristics of a person. Uniquely identify that person.

Examples:
Facial recognition data
Fingerprint data
Iris scan data.

Used for authentication, identification, access control, security and convenience.

Question 6

Objections to Biometrics

Answer 6

1. Inconvenience and Intrusion of Privacy. People may feel uncomfortable being photographed or fingerprinted. Can be seen as an intrusion into personal privacy.
2. Cost of the System. Biometric systems can be expensive to install and run. May increase fees for things like biometric passports.
3. Carrying Biometric Identity. People may object to carrying biometric ID and showing it to officials. Concern that police could target certain groups.
4. Surveillance Concerns. Facial recognition databases could allow unauthorised surveillance. Officials could track people through CCTV monitoring.
5. System Errors. Biometric systems can misidentify individuals. Errors more likely in poor lighting or unclear CCTV after a crime.

Question 7

Hacking

Answer 7

Black Hat Hacking. Hackers who break into systems illegally. Aim to steal data, cause damage, or make money. Considered criminal activity.
White Hat Hacking. Ethical hackers who have permission to test systems. Aim to find weaknesses so they can be fixed. Work to protect organisations.

Question 8

Penetration Testing

Answer 8

Penetration Testing is a planned, authorised test to check system security in which testers act like attackers to find vulnerabilities. Helps organisations improve their defences and is often carried out by trained white-hat professionals.

Question 9

Internal Penetration Test

Answer 9

Test carried out from inside the organisation’s network. Checks what damage an insider or someone who broke in could do.

Question 10

External Penetration Test

Answer 10

Test carried out from outside the organisation. Checks internet-facing systems.

Question 11

Network Penetration Test

Answer 11

Tests servers, routers, switches, and network security. Looks for open ports, weak services, misconfigurations. Can be internal or external.

Question 12

Web Penetration Test

Answer 12

Tests websites, web apps, logins, APIs. Looks for issues like SQL injection, broken authentication. Very common in modern organisations.

Question 13

Blind Penetration testing

Answer 13

The tester is given minimal information. Often only the organisation’s name or the target domain. No network diagrams, no internal access, no credentials.
The test simulates a real external attacker. Because real attackers don’t get documentation. The tester must discover everything themselves.
It measures two things: How secure the system is. How quickly the organisation detects an attack.
It usually costs more and takes longer because the tester spends a lot of time gathering information.