Compression, Encryption and Hashing A Level Resources

A Level Computer Science: Compression, Encryption and Hashing

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Frequently Asked Questions

Why is file compression important?

File compression is crucial because it helps reduce the size of files, allowing for efficient storage and transmission of data. Compressed files occupy less storage space, making it possible to store more data on a device or transfer files more quickly over networks. Compression also plays a vital role in optimizing download times for images, audio, and videos from the internet.

How are different types of files compressed?

Different types of files, such as text, images, audio, and videos, are compressed using various techniques. Text files can be compressed using algorithms like run-length encoding or Huffman coding, which exploit patterns in the text to reduce redundancy. Image and video files often employ lossy or lossless compression algorithms like JPEG or MPEG, respectively, which remove or reduce non-essential data to reduce file size while preserving acceptable quality. Audio files can use compression methods like MP3 or AAC to achieve similar outcomes.

What are the effects of compressing a file?

When a file is compressed, it undergoes a transformation that reduces its size by removing redundancy or non-essential data. The effects of compression can vary depending on the compression method used. Lossy compression techniques may result in a slight loss of quality in images, audio, or video due to the removal of some data. Lossless compression methods, on the other hand, preserve the original data without any loss in quality. It is important to strike a balance between compression ratios (file size reduction) and maintaining acceptable quality for the intended purpose of the file.

What are the various file formats?

There are numerous file formats, each designed for specific types of data. Common file formats include TXT for plain text, JPG/PNG for images, MP3/WAV for audio, and MP4/AVI for videos. Additionally, there are specialized file formats for documents (such as DOCX and PDF), spreadsheets (XLSX and CSV), and many more. Each file format has its own specifications, advantages, and limitations, catering to different needs and applications.

How does encryption contribute to data security?

Encryption plays a critical role in data security by converting data into an unreadable format using cryptographic algorithms. It ensures that only authorized parties can access and decipher the information. Symmetric encryption utilizes a single key for both encryption and decryption, while asymmetric encryption employs a pair of keys: a public key for encryption and a private key for decryption. Encryption protects sensitive information during storage, transmission, and communication, preventing unauthorized access and maintaining confidentiality and integrity of data.