# Securing the Digital Realm: A Comprehensive Guide to Cryptographic Hashing and Its Applications

Have you ever heard of hashing? Don’t worry, we’ll explain it to you. We’ll go over everything you need to know about hashing, such as what it is, how it operates, why people make use of it, and some popular hashing algorithms, in this blog.

Hashing is a mathematical algorithm used to transform plaintext into a unique text string or ciphertext. That sounds perplexing, doesn’t it? Don’t worry, we’ll walk you through it with an example.

Let’s say your name is Shivam and you don’t want anyone to know about it. You are able to represent your name differently in the format of a unique text string by using a hashing algorithm. Only you will be able to tell this particular text or number.

# What exactly is hashing?

Before talking about hashing we have to take a look at what is hash. So, A hash is a mathematical computation that transforms an arbitrary length input into an encrypted length output. As a result, its unique hash will always be the same size regardless of the original amount of data or file size involved.

Hashing is a cryptographic technique for converting any type of data into a unique text string. There is a predetermined output for any given input. In simpler terms, putting plaintext into a hashing algorithm yields the same result. Assume you change anything about the hashing algorithm’s input or plaintext. The hashing output varies as well.

## How does hashing work?

### Key

The key is also known as the input data to be hashed. A key can be in almost any format. A string of text, a list of numbers, an image, or even an application file could be used.

### Hash function

The hashing function, which uses the key and transforms it into a fixed-length string of characters, is at the heart of any hashing process. But how does this work exactly? How can a title and a whole novel both be reduced to the same number of characters?

The trick is to divide the data into equal-sized blocks. The most common hashing algorithms use block sizes ranging from 160 to 512 bits. A bit is the fundamental unit of computer information, and it corresponds to either binary 1 or binary 0.

Because most files and datasets are much larger, the algorithm divides the data into 512-bit chunks. If our data is 1024 bits long, the algorithm first runs the SHA-1 function on the first half of the data, generating a hash value, and then combining this first hash value alongside the second half of the data to produce a final hash value. For larger inputs, the process is repeated until the hashing algorithm has processed all 512-bit chunks.

### Hash Value

The hash value is the hash function’s final output, and it should ideally be unique to each input. Hash values may only be used at once for data authorization or digital signatures, or they may be stored in a hash table for quick search.

## The characteristics of hashing algorithms

There are multiple approaches that hashing algorithms and functions take for transforming data into hash values, but they all have a few things in common.

### Collision resistance:

Collision resistance is a requirement for a secure hashing algorithm. This means that finding two different inputs that produce the same hash value should be impossible to compute. This is critical for data integrity and security applications because it blocks attackers from forging messages or interfering with data while remaining undetected.

### Preimage resistance:

A secure hashing algorithm should also be resistant to preimages. This means that finding the original input data given the hash value should be computationally impossible. This is critical for password storage because it prevents attackers from recovering passwords based on hash values.

### Deterministic:

A deterministic hashing algorithm is required. This means that for the same input data, it must always produce the same hash value.

# Some well-known Hashing Algorithms

### MD-5 (Message-Digest Algorithm 5)

MD5 (Message-Digest Algorithm 5) is a popular cryptographic hash function that generates a 128-bit (16-byte) hash value from any length message. Ronald Rivest created it in 1991 to replace an earlier hash function, MD4, and it was specified as RFC 1321 in 1992. MD5 has been used in a variety of applications such as file verification, digital signatures, and password storage.

However, in 2005, vulnerabilities in MD5 were discovered, rendering it insecure for certain applications. As a result, MD5 has been phased out of many applications and is no longer considered secure for sensitive data.

### SHA(Secure hashing algorithm)-1 & SHA-256

SHA-1 (Secure Hash Algorithm 1), introduced in 1995, succeeded MD5 and provided enhanced security. It was adopted as the industry standard for digital signatures, password storage, and file integrity verification. However, vulnerabilities were discovered in 2005, casting doubt on SHA-1’s long-term security.

In response to the shortcomings of SHA-1, the SHA-2 hash function family was introduced in 2001. SHA-2 has four variants, each with a different output length: SHA-224, SHA-256, SHA-384, and SHA-512. With a hash value of 256 bits, SHA-256 has emerged as the most widely used and trusted SHA-2 variant.

### BLAKE-2

BLAKE-2, a hash function family introduced in 2012, has emerged as a promising replacement for SHA-2. Its high performance and strong security make it an appealing choice for a wide range of cryptographic applications. Several cryptographic libraries have adopted BLAKE-2, which is regarded as a strong contender for future security standards.

### Bcyrpt and Scrypt

Bcrypt is also known as a password hashing algorithm. Niels Provos and David Mazières created it in 1999. Simultaneously, Colin Percival debuted the scyrpt in 2009. The two hashing Algorithms’ key derivation functions are both designed to be shown on a computer. However, when compared to Bcrypt, Scrypt is the most secure.

Bcryot serves as the basis for simple passwords, whereas Scrypt is used as a proof-of-work algorithm in many cryptocurrencies.

# Applications of Hashing

Hashing is used in a wide range of applications, including cryptocurrency, blockchain, and data privacy. Here are a few examples of how people use hashing on a daily basis.

### Data Integrity Verification

Hashing is commonly used to ensure that data has not been tampered with or modified during transport or storage. Users can easily identify if data has been altered by comparing the hash value of a file or message to a known hash value. This is critical for software distribution, file sharing, and digital archiving applications.

### Cryptocurrency

Cryptographic hashes are most commonly used in cryptocurrencies. It is used to send anonymous transaction data. It additionally serves to generate public jets and to perform block hashing. As an example, consider Bitcoin. Its algorithm employs the SHA – 256 hash function.

### Blockchain Technology

A cryptographic hash function is used in blockchain technology to protect connections and message transfer between blocks in a chain. Each block holds its own hash as well as the hash of the previous block, forming a securely encrypted chain of blocks.

### Password Storage

Hashing is essential for securely storing passwords. Hashing algorithms turn passwords into unique hash values rather than storing them in plain text, which is prone to unauthorized access. When a user logs in, their password is hashed and compared to the previously saved hash value. The password has been verified if the hash values match. Even if an attacker breaches the database, they will not be able to retrieve passwords.

# Conclusion

In this blog, we looked at the comprehensive overview of hashing, its applications, and the most commonly used hashing algorithms today. Hashing is a fundamental cryptographic technique that ensures data integrity, security, and authenticity in a variety of digital domains. Hashing algorithms will remain vital instruments in preserving our digital information as technology evolves and the necessity for secure data security grows.