\chapter{Cyber security} Cyber security is the study of the relation between computers, networks, and malicious threats and attacks that they are vulnerable to. \section{Threats} \textit{Social engineering} involves exploiting people directly for access or information. \textit{Blagging} involves obtaining information through deception or impersonation, such as calling someone whilst posing as a friend. \noindent\textit{Phishing} is posing as a legitimate organisation to obtain personal information, generally through email. \noindent\textit{Pharming} involves a bogus website that imitates a legitimate one. \textit{Shouldering} involves watching somebody enter their personal information. \noindent\textit{Malicious code} is code written to do bad. A \textit{virus} does damage on a computer and spreads itself on a user's device over the internet. \textit{Spyware} is software that monitors, logs, and sends information to the spy. For example, a keylogger may record every key a user presses and send it to the spy so that information such as a password can be extracted. \textit{Adware} is a program that is designed to show the user advertisement and a \textit{Trojan} is any malware that poses as a legitimate software. \noindent\textit{Weak passwords} or \textit{misconfigured access rights} may allow an attacker easy access to unauthorised data. Access rights would normally restrict certain information from certain users. \noindent\textit{Removable media} such as a DVD or USB flash drive is a vector by which malware can spread, particularly when distributed, such as at an event \noindent\textbf{Unpatched or outdated} software may contain widely known vulnerabilities, which an attacker could exploit. \section{Threat prevention} \subsection{MAC address filtering} A \textit{media access control address} is unique to each device. Filtering MAC addresses could mean: \begin{itemize} \item \textit{whitelisting}, or only allowing authorised devices to connect to or \item \textit{blacklisting} which is blocking certain devices from a network. \end{itemize} However, this is bypassable through MAC address \textit{spoofing}, where a device can appear to have a MAC address other than its own. \subsection{Firewall} A firewall blocks internet activity. This may be blocking access to certain sites, or preventing external activity from potential attackers. \subsection{Authentication} Authentication is the validation of identity through credentials. The most common form of this is through a username and password. It can also be through physical objects such as cards (such as credit card) and through biometric methods such as fingerprints. CAPTCHA (tests that determine if a user is a human) and e-mail verification (where the user must respond to an e-mail only they could have received) can also be used as authentication and to ensure that the user is human and not an automated attack. \subsection{Encryption} Encrypted data is encoded in such a way that only the sender and recipient and sometimes only recipient can decode the data and read the information. To anyone else (such as an eavesdropper), the data is meaningless.