Data diddling is the unauthorized alteration of data before or during its entry into a computer system.

A 'cracker' is specifically defined as someone who gains unauthorized access to computer systems or networks with malicious intent, often to commit theft, vandalism, or other illegal activities. While 'hacker' is a broad term that can encompass both ethical (white-hat) and malicious (black-hat) activities, 'cracker' precisely denotes the malicious actor. An 'Ethical Hacker' (or penetration tester) performs authorized security testing. A 'Cyber Security Analyst' works to protect systems from threats. A 'Network Administrator' manages and maintains network infrastructure.

While annoying, spam (unsolicited email) is generally considered a nuisance rather than a direct security threat like viruses or hacking.

A MAC (Media Access Control) address is a unique identifier assigned to a network interface controller (NIC) for communication within a network segment (like an Ethernet LAN). This address operates at the data link layer (Layer 2) of the OSI model. Standard MAC addresses are 48 bits long. They are typically represented as six groups of two hexadecimal digits, separated by hyphens, colons, or dots (e.g., 00:0A:95:9D:68:16). Each hexadecimal digit represents 4 bits, so 6 groups of 2 hex digits means 12 hex digits in total, and 12 * 4 bits/hex digit = 48 bits.

A DoS attack floods the server with requests, making it inaccessible to users. [cite: 271]

The Data Protection Act is a key piece of legislation in the United Kingdom (UK). The original act was passed in 1984 and has been updated several times, most recently in 2018 to incorporate the EU's GDPR, to govern the protection of personal data.

A password (Option A) is a secret word, phrase, or string of characters used for authentication to prove identity and authorize access to a computer system, application, or data. It is the most common and fundamental security mechanism for controlling access. A username (Option B) identifies the user but doesn't grant access on its own. A PIN (Option C) is similar to a password but is typically a shorter, numeric code used for specific purposes like ATM transactions or mobile device unlocking. A digital signature (Option D) is a cryptographic technique used to validate the authenticity and integrity of a digital message or document, not primarily for system access.

Relatedness in ethics refers to the perceived proximity and connection to individuals who will be impacted by a decision.

Encryption converts readable data into an unreadable format to protect it from unauthorized access during transmission.

A backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event.