1.3.1 Compression, Encryption and Hashing

Types of compression

• Lossy

• Lossless

• Symmetric

• Asymmetric

Types of encrpytion

• Lossy

• Lossless

• Symmetric

• Asymmetric

Compression

• Used to reduce the file size

• Allows files to be sent more efficently

• Scrambles data into meaningless content unless you have a key

• Results in permanent data loss

• Requires decompression to reverse process

The process uses an _________ to do the actual compression

Compression means that when sending data over a network more bandwidth is required.

• TRUE

• FALSE

Compression technique that results in a permanent loss of data.

• Lossy

• Lossless

Lossy compression

• Algorithm removes the least significant data.

• The data that was removed is recreated from the data that remains.

• Used with sound and image files.

• Less effective at reducing file size.

• When decompressed the contents are identical to the original.

Lossless compression

• Algorithm removes the least significant data.

• The data that was removed is recreated from the data that remains.

• Used with sound and image files.

• Less effective at reducing file size.

• When decompressed the contents are identical to the original.

Works by finding contiguous binary patterns and replacing them with a single instance of the pattern and a number that specifies the quantity.

• Run length encoding

• Dictionary encoding

Images are made up of