1.3.1 Compression, encryption and hashing - Josh O Flashcards
What is Hashing?
One-way transformation of data, which is used to store things like passwords in databases
What is Compression?
A process used to reduce the size of a file
Why is Encryption needed?
It is used to keep data secure when its being stored or transmitted
What is Lossy Compression?
Reduces the size of the file, but also removes some information
What is Lossless Compression?
Reduces the size of a file, without losing any information
What is Asymmetric Encryption?
Encryption with a public encryption key, but private decryption key that only the recipient has
What is Symmetric Encryption?
An encryption technique where the same key is used to encrypt and decrypt data
What is Run-Length Encoding?
A type of lossless compression, where repeated data is stored as single values, with their counts
What could happen with Lossy Compression?
Images become pixelated, or audio recordings become less clear
Why is Compression important?
It is important for sharing files over the Internet because the larger a file is the longer it takes to transfer
What type of Compression is Dictionary Encoding?
Dictionary Encoding is a method of Lossless Compression
What is the difference between lossy and lossless compression?
Lossy compression reduces file size by removing some data, while lossless compression reduces file size without losing any data
Give an example of a lossless compression algorithm.
An example of a lossless compression algorithm is Run-Length Encoding
What is Huffman Coding?
Huffman coding is a lossless compression method that uses variable length codes based on frequency of occurrence of each symbol
How does lossy compression affect multimedia files?
Lossy compression reduces file size by removing data, often reducing quality
