Question 253 : What’s the difference between encoding, encryption, and hashing?

1-Encoding is the process of téléchargementconverting data into a format required for a number of information processing needs, including:

  • Program compiling and execution
  • Data transmission, storage and compression/decompression
  • Application data processing, such as file conversion

In computer technology, encoding is the process of applying a specific code, such as letters, symbols and numbers, to data for conversion into an equivalent cipher.

For example Encoding is used to reduce the size of audio and video files. Each audio and video file format has a corresponding coder-decoder (codec) program that is used to code it into the appropriate format and then decodes for playback

2-Encryption provides confidentiality and prevents unauthorized disclosure of data. Encrypted data is in a cipher text format that is unreadable. Attackers can’t read encrypted traffic sent over a network, or encrypted data stored on a system. In contrast, if data is sent in clear text, an attacker can capture and read the data using a protocol analyzer.

The two primary encryption methods are symmetric  and asymmetric. Symmetric encryption(ex: DES , 3DES, AES) encrypts and decrypts data with the same key. Asymmetric encryption (ex: RSA )  encrypts and decrypts data using a matched key pair of a public key and a private key.

These encryption methods include two elements:

  • Algorithm. The algorithm performs mathematical calculations on data. The algorithm is always the same.
  • Key. The key is a number that provides variability for the encryption. It is either kept private and/or changed frequently

3-Hashing is an algorithm performed on data such as a file or message to produce a number called a hash (sometimes called a checksum). The hash is used to verify that data is not modified, tampered with, or corrupted. In other words, you can verify the data has maintained integrity.

A key point about a hash is that no matter how many times you execute the hashing algorithm against the data, the hash will always be the same as long as the data is the same.

Hashes are created at least twice so that they can be compared. For example, you can create a hash on a message at the source before sending it, and then again at the destination. If the hashes are the same, you know that the message has not lost integrity. Message Digest 5 (MD5) and the Secure Hash Algorithm (SHA) family are popular hashing algorithms.

Remember this : Encoding involves the use of a code to change original data into a form that can be used by an external process so it  should not be confused with encryption, which hides content and Hashing is an algorithm used to verify data integrity.

src: Security+ Study Guide,Darril Gibson.

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