CHMOD
CHMOD: Understanding File and Directory Permissions
In Unix-like operating systems (such as Linux and macOS), CHMOD is a command used to change the file or directory permissions. Permissions control who can read, write, or execute a file or directory.
Permission Structure
Permissions are grouped into three categories:
Null Cipher
The Null Cipher, also known as the Null Encryption or Null Message, is a simplistic cryptographic technique where specific letters or symbols are deliberately left blank or null in a message. Instead of using complex algorithms or substitutions, the Null Cipher relies on the absence of characters to convey hidden information.
NATO: North Atlantic Treaty Organization
It is a phonetic alphabet that uses 26 code words.
These words are used to ensure oral communication is clearly understood.
The NATO, North Atlantic Treaty Organization, phonetic alphabet became effective in 1956 and just a few years later became the established universal phonetic alphabet.
However, it took several adaptations before the version used today came into effect.
Morse
ORIGIN: USA
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes or dits and dahs. Morse code is named after Samuel Morse, an inventor of the telegraph
Morse code is usually transmitted by on-off keying of an information-carrying medium such as electric current, radio waves, visible light, or sound waves. The current or wave is present during the time period of the dot or dash and absent during the time between dots and dashes
Map Cipher
The Map Cipher, also known as the Route Cipher or Matrix Cipher, is a method of encryption that involves rearranging characters of a message according to a predefined route or pattern on a grid or map. It is a type of transposition cipher, where the original letters of the plaintext are preserved, but their order is changed to create the ciphertext.
Keyboard Code
Keyboard Code, also known as Keyboard Cipher or Keyboard Encryption, is a simple and straightforward method of encrypting and decrypting messages using a keyboard layout as a reference. It is a type of substitution cipher, where each letter of the plaintext is replaced with a corresponding letter from the keyboard layout.
JavaScript
/ˈdʒɑːvəˌskrɪpt/
A Language for Web Interactivity
JavaScript, commonly abbreviated as JS, was developed by Brendan Eich at Netscape in 1995. Originally known as LiveScript it later adopted the name JavaScript to capitalize on the popularity of Java at the time. Unlike its namesake, JavaScript is a scripting language designed explicitly for client-side web development, enabling dynamic and interactive web experiences.
Java
/ˈdʒɑːvə/
The Language for Platform Independence
Java, a widely used and versatile programming language, was introduced by James Gosling and his team at Sun Microsystems in the early 1990s. Originally named Oak it later evolved into Java, with its first public release in 1995.
Hypertext Markup Language
/ˌhaɪpəˌtɛkst ˈmɑːrkʌp ˈlæŋɡwɪdʒ/
Hypertext Markup Language (HTML), pronounced as /ˌhaɪpəˌtɛkst ˈmɑːrkʌp ˈlæŋɡwɪdʒ/, is a standard markup language used to create and structure content on the World Wide Web. HTML serves as the foundation for building web pages by defining the structure and layout of elements within a document.
Grid Transposition Cipher
The Grid Transposition Cipher is a method of encryption that involves rearranging the characters of a message based on a predetermined grid pattern. It is a type of transposition cipher, where the original letters of the plaintext are maintained, but their positions are altered to create the ciphertext.