Archives: Theory

Logic Circuits

What is a logic circuit? When logic gates are connected they form a circuit.  Logic circuits are designed to perform a particular function, understanding the nature of that function requires a logic circuit truth table. How…

Memory and Storage

Computer memory / storage can be classified in three ways; primary, secondary and off-line. Primary Primary memory is the computer’s main memory, which is directly accessible by the CPU and often much faster than secondary storage….

Internet Service Provider

An Internet Service Provider (ISP) is a company that provides users with access to the internet. It would be impractical and costly for individuals and most companies to connect to the internet infrastructure directly, hence the…

DOS Attack

Denial of service attacks (DOS attack) are carried out with the intention of stopping legitimate users from accessing a web server or network. The denial of service is achieved by flooding a network or server with so…

Pharming

Pharming is a term used to describe a cyber scam where malicious code redirects a user to a fake website without their knowledge. Unlike phishing, pharming scams do not occur as a result of the user…

Sensors

Sensors are input devices that record data about the physical environment around it. Sensors send data to a microprocessor (computer).  They do not make judgements, decisions or control any output devices. There are many types…

Asymmetric Encryption

Asymmetric encryption (sometimes called public key encryption) is a form of encryption where a pair of keys are responsible for encrypting and decrypting data. This is different to symmetric encryption where the same key is used to…

Symmetric Encryption

What is encryption? Encryption is the conversion of data (plain text) into a form that is unreadable (ciphertext). Encryption allows us to protect data during transmission and make it useless if hacked from a server. The…