What is the Difference Between Hashing and Encryption

The main difference between hashing and encryption is that the hashing output cannot be converted back to the original message while the encrypted message can be converted back to the original message.

It is important to ensure that exchanging information on the web is secure. There are various methods to make the data secure. Two of them are hashing and encryption. Hashing applies hashing functions on the data and transforms it to a numerical value. Matching the hashes of sent and received messages ensures that both are the same and it helps to verify data. On the other hand, encryption is the process of converting the original data that should be transmitted into an unrecognizable format so that unauthorized parties cannot read it. It helps to transfer the data securely.

Key Areas Covered

1. What is Hashing
     – Definition, Functionality
2. What is Encryption
     – Definition, Functionality
3. What is the Difference Between Hashing and Encryption
     – Comparison of Key Differences

Key Terms

Hashing, Encryption

What is Hashing

Hashing is a mathematical operation that converts data into a unique number generated from a string of text. The output is known as message digest or hash. It is possible to perform hashing on any piece of data. The input data can have an arbitrary length but the output is always fixed. In hashing, data goes through the hashing algorithm and provides a unique output but it is not possible to convert it back to the original data.  A unique piece of a data will always produce the same hash. Hashing is easier to perform, but it is difficult to reverse. MD5, SHA1, and SHA-256 are some hashing functions.

Figure 1: Hashing

For example, a user can create an email account by providing an email address and a password. The email provider does not save the password. It runs the password through a hashing algorithm and saves the hash of the password. When attempting to open the email account, the email provider checks the hash of the password and the hash of the originally saved password. When the two hashes are the same, the user gets the authorization to access the email.

What is Encryption

Encryption is the process of converting the original message into an unrecognizable form so that it cannot be identified by unauthorized parties. It is performed at the sender’s end. The new form of the message is totally different from the original message. Therefore, it is a great mechanism to transmit data securely via a communication channel. The sender uses an encryption algorithm and a key to convert the original message into an encrypted message. The encrypted message is also called the ciphertext. At the receivers end, this encrypted message is converted back to the original message using decryption algorithms and a key. This is called decryption.

Figure 2: Encryption and Decryption

Furthermore, there are two methods used in encryption and decryption. They are called symmetric and asymmetric encryption. Symmetric encryption uses the same key for both encryption and decryption. Asymmetric encryption uses two keys (public and private key) for encryption and decryption.

Difference Between Hashing and Encryption

Definition

Hashing is the process of using hash functions on data to map it to a fixed size numerical output.  Encryption is the process of encoding a message or information in such a way that only authorized parties can access it. 

Basis

The basic difference between hashing and encryption is that hashing converts the data to message digest or hash, which is a number generated from a string of text while encryption uses encryption algorithms and a key to convert the message to transmit into an unrecognizable format.

Use of Keys

Hashing does not use any keys while Encryption uses keys. This is another difference between hashing and encryption.

Objective

One important difference between hashing and encryption is that the objective of using hashing is to verify data while the objective of encryption is to transmit data securely.

Usage

Hashing is used for sending passwords, files and for searching. Encryption is used for transferring sensitive business information, etc.

Reversibility

Furthermore, we can identify a difference between hashing and encryption in their reversibility, That is, the hashing output cannot be reversed back to the original message. The encrypted message can be transformed into the original message by using decryption algorithms and appropriate key.

Used Functions and Algorithms

MD5, SHA1 and SHA-256 are some hashing functions. C4, AES, DES, 3DES are some Symmetric Encryption algorithms. Diffie-Hellman and RSA algorithm are some Asymmetric Encryption algorithms.

Conclusion

In conclusion, the main difference between hashing and encryption is that hashing output cannot be converted back to the original message or data while encrypted message can be converted back to the original message.

Reference:

1. “Cryptography Hash Functions.” Www.tutorialspoint.com, Tutorials Point, Available here.
2. Ray, Shaan. “Cryptographic Hashing – Hacker Noon.” Hacker Noon, Hacker Noon, 3 Nov. 2017, Available here.

Image Courtesy:

1. “Hash function” 公有领域, via Commons Wikimedia
2. “Encryption1” By Munkhzaya Ganbold – Own work (CC BY-SA 4.0) via Commons Wikimedia