Computer science

?
  • Created by: SouthoS01
  • Created on: 17-10-19 11:00
View mindmap
  • Yr9 computer science
    • Ciphers
      • Substitution
        • A substitution cipher is where you systematically substitute one character for another, often using a key
        • Julius Caesar invented a type of substitution cipher called the Caesar cipher. This is where you shift each letter in the alphabet 3 times to the right against the same alphabet.
          • Why?
            • So the Roman army could communicate and send messages in this code without other spies understanding where or what the army would do next
        • A key is how many spaces you move the alphabet across
      • Transposition
        • A transposition cipher is a way of changing plain text into cipher text systematically by changing the position of letters in a word
        • An example would be what the Greeks used using the Scytale roll
      • Cipher text is the coded message
      • Plain text is the normal, everyday text and characters that we use
      • Cryptanalysis is the process to decipher a code without knowing the key
    • Python
      • Print: this then shows the text as part of the code when run
      • " " " these allow the user to make notes or keep code but not allow it to run
      • Variables: a storage area in the memory of a computer given a label. The contents of a variable can be changed throughout the program
      • Data Types
        • Real/float numbers are numbers with a decimal place
        • Strings are lines that is a sequence of characters
        • Integers are whole numbers that are above 0 and have no decimal places
        • Loops
          • while
          • for
        • Boolean is a variable that has two outcomes e.g. true or false
      • if, elif, else
        • if: runs when a statement becomes true
        • elif: this runs when there is more than one option to happen, shortened version of else if
        • else
      • input()

Comments

No comments have yet been made

Similar Computing resources:

See all Computing resources »See all Computer systems resources »