Data compression and encryption pdf

Can a file be both compressed and encrypted?
When compressing and encrypting a file, the recommended order is to compress the file first and then encrypt it.
This process is known as “compress-then-encrypt.”.
Can a file be compressed and encrypted?
Some tape devices make use of their own compression when you store data.
By definition, data that is encrypted should not be compressible; if you can compress encrypted data it is probably not well encrypted.
You might want to compress your data before you encrypt it using the COMPRESSION option of Encryption Services..
What are the techniques of data compression and encryption?
Data Encryption uses an encryption algorithm to transform the data into a secure form.
Data Compression uses a compression algorithm to reduce the size of the data.
Data Encryption uses an encryption key to generate a secure form of the data..
What is data compression and encryption?
Compression reduces the amount of space and bandwidth needed to store and transmit data, which can improve efficiency, speed, and cost.
Encryption transforms data into an unreadable form that can only be decrypted with a key, which can prevent unauthorized access, tampering, and leakage..
By definition, data that is encrypted should not be compressible; if you can compress encrypted data it is probably not well encrypted.
You might want to compress your data before you encrypt it using the COMPRESSION option of Encryption Services.
Data encryption is a way of translating data from plaintext (unencrypted) to ciphertext (encrypted).
Users can access encrypted data with an encryption key and decrypted data with a decryption key.
It is better to compress before encrypting.
Any proven block cipher will reduce the data to a pseudo-random sequence of bytes that will typically yield little to no compression gain at all.

Traditionally, data from a source is first compressed and then encrypted before it is transmitted over a channel to the receiver. On the other hand, the

What are the advantages and disadvantages of encryption?

Sometimes significantly.
This has huge benefits such as:

reduced storage capacity to save the same amount of data

Transmission of encrypted data is faster because the amount of data transmitted is considerably less.
There are many forms of encryption:some extremely week, some very complex.

What is standard encryption method?

Well-known symmetric encryption methods include:

the now-outdated Data Encryption Standard (DES) and its successor
the Advanced Encryption Standard (AES)

Data Encryption Standard (DES) DES is a symmetric encryption method that was developed by IBM in the 1970s and standardized in 1977 by the US National Institute of Standards and Technology (NIST).

What is the difference between encoding and encryption?

Encoding is needed to make data as clear as possible for both the recipient and for anyone using the same notation.
While encoding is needed to make information understandable for everyone, encryption is used for the opposite purpose.
It is intended to protect data from anyone without a decryption key.

Abstract

We live in a digital era in which communication is largely based on the exchange of digital information on data networks

Introduction

We live in a digital era in which the way we communicate has dramatically changed. We can communicate digital files at any time, on any device

Data Compression and Cryptography

Today the way we communicate has dramatically changed. We communicate digitally and we aim to have an efficient and secure communication

Text and One-Dimensional Digital Data

One-dimensional data, for example, textual data, programs, and object codes, are generally lossless coded because the end user

Images and Two-Dimensional Digital Data

Two-dimensional data, i.e., digital images, are generally lossy coded because the human end user is not capable of noticing small pixel errors

Video and Three-Dimensional Digital Data

Digital video is an example of three-dimensional data

Conclusions and Future Research

We live in a digital era in which the way we communicate has dramatically changed. We can communicate digital files at any time, on any device

Acknowledgments

The author would like to thank the students Alessandro Sacco, Luigi Amitrano, Paolo Anastasio

What is data compression?

Data Compression can be defined as the coding of data to minimize its representation

The compression process is called lossless if the original one can be exactly reconstructed from the compressed copy; otherwise it is called lossy

The theoretical background of the data compression techniques is strong and well established

What is the difference between data compression and encryption?

These two operations are data compression and encryption

The enemy of compression is randomness, but on the other side encryption needs to bring randomness into the digital data to bring security

This is why, when we have to perform both compression and encryption, we will always compress first the data and then encrypt it

When should encryption be applied before compression?

Encryption can also be applied before compression in some particular situations such as when it is desired to transmit redundant data over an insecure and bandwidth-constrained channel

Traditionally, data from a source is first compressed and then encrypted before it is transmitted over a channel to the receiver