Compression, Encryption and Hashing.

James McColgan
Mind Map by James McColgan, updated more than 1 year ago
James McColgan
Created by James McColgan over 4 years ago


Compression, Encryption and Hashing.

Resource summary

Compression, Encryption and Hashing.
  1. Compression.
    1. Compression is a reduction in the number of bits needed to represent data. Compressing data can save storage capacity, speed file transfer, and decrease costs for storage hardware and network bandwidth.
      1. One type of compression is lossless. Lossless compression doesn’t reduce the quality of the file at all. No data is lost, so lossless compression allows a file to be recreated exactly as it was when originally created. You can remember lossless by thinking that the data is not lost, lossless.
        1. Another type of compression is Lossy. Lossy compression removes some of a file’s original data in order to reduce the file size. This might mean reducing the numbers of colours in an image or reducing the number of samples in a sound file. This can result in a small loss of quality of an image or sound file.
      2. Encryption.
        1. Symmetric encryption’s job is to take readable data, scrambles it to make it unreadable then unscramble it again when it’s needed. The most important thing to remember about symmetric encryption is that both sides—the encrypter, and the decrypter—need access to the same key.
          1. Asymmetric encryption also takes readable data, scrambles it, and unscrambles it again at the other end, but there’s a twist: a different key is used for each end. Encrypters use a public key to scramble the data, and decrypters use the matching private (secret) key on the other end to unscramble it again.
          2. Hashing.
            1. Hashing is what is actually happening when you hear about passwords being “encrypted”. Strictly speaking, hashing is not a form of encryption, though it does use cryptography. Hashing takes data and creates a hash out of it, a string of data with three important properties: 1.the same data will always produce the same hash, 2. it’s impossible to reverse it back to the original data given knowledge of only the hash, 3. it’s infeasible to create another string of data that will create the same hash (called a “collision” in crypto parlance)
            Show full summary Hide full summary


            A level Computing Quiz
            Zacchaeus Snape
            Types and Components of Computer Systems
            Jess Peason
            Input Devices
            Jess Peason
            Output Devices
            Jess Peason
            Kwame Oteng-Adusei
            Pack of playing cards answer
            Karl Taylor
            Code Challenge Flow Chart
            Charlotte Hilton
            Computer science quiz
            Ryan Barton
            GCSE Computing - 4 - Representation of data in computer systems
            Data Structures & Algorithms
            Reuben Caruana
            OCR gcse computer science
            Jodie Awthinre