# Cryptographic Hash Function: An Overview

## Introduction

Every single internet user encounters and usesÂ Cryptographic Hash FunctionsÂ daily. Cryptographic hash function primarily acts as a backbone in todayâ€™s internet world, securing against cyber threats that are part and parcel of everyday life.

Have you ever wondered how e-mail passwords are saved and retrieved securely for every user on the web or how files are downloaded from the internet? Well, the answer lies in the process of encrypting the data or password, storing it in a database, and retrieving it whenever a correct match is identified.

For instance, the system grants access to the user when he tries to log in to his e-mail account in the future with the same credentials. It is done only after a match in the encrypted data specific to the userâ€™s input data; in this case, the password is being established. This process is done using theÂ Cryptographic Hash Function.

## 1. What is a Cryptographic Hash Function (CHF)?Â

Cryptographic Hash Function DefinitionÂ – CHF, in simple cybersecurity terms, refers to a computer algorithm that helps in authenticating users and securing their data against any breach by others trying to gain access using hacking or other unethical means. It uses system-generated encrypted data specific to each user input data and authenticates future access when a match in the user input data is identified.

AÂ Cryptographic Hash Function converts arbitrary input data into fixed-size output data. It is mainly used to authenticate the validity of the data specified and is widely used in cryptocurrencies. It is a one-way function â€“ input data is hashed into an algorithm that produces a unique string of data but is unable to decipher its original data. Hashing is critical in maintaining the integrity of the data and is regarded as the backbone of the blockchain technology used in cryptography.

Hashing is also known by different names, including Checksum, and Digest, etc.

## 2. Cryptographic Hash Functions Properties

The following properties of Cryptographic Hash Functions determine the effectiveness of a cryptographic tool and thus its impact on data security.

1. Deterministic Character â€“ Any given password will generate the same encrypted data or the hash value. In other words, there is a unique and corresponding encrypted text for every password or user data.
2. Non-predictability â€“ The password or the user input data cannot be reproduced or guessed based on a prediction from its hash value. Therefore, it makes it impossible for any hacker to reproduce or predict a password from the hash value even if he gets hold of it.
3. Non-reversibility â€“ This function restricts hackers to get access to the password using its corresponding hash value. It is a one-way function in which the hash value cannot be used to regenerate the input data.
4. Collision Resistance â€“ No two input data can generate the same hash value. This property makes it difficult for any hacker to find the same hash value with two different input values.
5. Diffusion Effect â€“ Any changes to the password or input value result in a significant change in the hash value that predicts its unpredictable nature. In other words, any slight change in the password or user value gives a corresponding encrypted text or result that is different from the previous value.

## 3. How do Hash Functions Work?

Hashing is a computer algorithm designed to compare data and authenticate the information by checking its integrity. This function converts an arbitrary length data into a fixed-length encrypted text or value, also called the checksum. As the number of characters assigned to the checksum increases, it becomes challenging to reverse this operation. For instance, MD5 checksum uses a 32 character value; similarly, SHA-1 uses a 40 characters value, and SHA-2 generates 128 character values, and so on. Therefore, the likelihood of producing the same checksum for different user data gets reduced with the increase in the number of characters.

## 4. Variations inÂ Cryptographic Hash Function

Apart from the MD5 and SHA-1 Variations, the SHA-2 is a more popular one and has many variations used in cryptography. Especially in the Bitcoin industry, blockchain technology uses the SHA-256 hashing function, which a variation of the SHA-2. SHA-512 is another variant of the SHA-2, which is more secure and faster than SHA-256.Â

## 5. Application of Cryptographic Hash Function

Cryptographic Hash function AlgorithmsÂ are mainly used in the cryptocurrencies and in downloading files, password storage, and feeding data from databases. It provides security to password storage as an intruder cannot gain access login in using the hash values, nor can he derive the password from it. The most common usage ofÂ Cryptographic Hash FunctionÂ is in data integrity check wherein it assures the user about the authenticity of the information.

## 6. Cryptographic Hash Function Example

Cryptographic Hash Function exampleÂ includes authenticating digital signatures to gain access to digital documents, verifying message and file integrity, and storing and verifying passwords, etc. Digital signatures work on the premise that the sender, after satisfying the necessary prerequisites of authentication, provides the receiver with the required data without getting it altered in the process. The same process takes place for password and file verification using input values compared to their corresponding specific hash values.

## ConclusionÂ

Cryptographic Hash FunctionÂ acts like an entry barrier to cyber intruders and plays a major role in securing the modern-day information technology system. A soundÂ Cryptographic Hash FunctionÂ is needed to withstand any major threat that would destabilize the whole security apparatus. So, it becomes imminent for the global cybersecurity industry to find ways to bring in stronger and smarter technologies to tackle this menace.

One such measure that is being used along with hash functions is â€˜Salting.â€™ It uses some random data added to the password before the hashing process and stores it separately along with its checksum. Thus, it makes it even more difficult for hackers and intruders to gain access to the system.

It has become the backbone of the global cybersecurity apparatus and is powering several other industries that are gaining momentum that uses blockchain technology applications.

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