Hashing functions have become a vital part of cybersecurity, specifically for blockchain-based cryptocurrency protocols. They are further incredibly beneficial for software security and appear in almost all applications.
It’s a form of computer and software security model that helps sustain the integrity and authenticity of the data message. Often mistaken for encryption protocols, hashing is a different security model. It’s an important mathematical process that holds a critical role in public key cryptography.
From signing software with Code Signing Certificates to transferring sensitive information online, hashing is being used nearly everywhere. But what is hashing in cryptography and how does it work?
Let’s find out:
What is Hashing in Cryptography?
Contents
A hash function can have different meanings depending on the use and context. But a cryptographic hash function can be defined as a unique identifying value that’s assigned to any piece of information.
It’s a mathematical algorithm of a fixed size also known as a hash value or message digest used for hashing the arbitrary data value often known as “message”. This is a one-way hash function, meaning it’s practically infeasible to invert or reverse the computation value.
For instance, if you change the input data provided for hashing, the output will change. Also, mapping the arbitrary value from the hash value is hard or near to impossible. It gives deterministic output for any input data.
The hashing is primarily used for converting plain text into unique & special strings of data. No matter the size, it can hash any piece of information to always produce the same length of string digest or unique hash value.
This may sound confusing, so let’s simplify it a bit with an example. Let’s assume you don’t want to disclose your name to every digital platform. Now with the use of a hash function in cryptography, you can display your name with a unique string of text that can only be deciphered by you.
For instance, let’s say your name is Tony Mark. When hashed, it’d look like this:
Tony Mark = VLSu7818hVpKg6rU
How Does Hashing Work?
As we learned, cryptographic hashing is a mathematical operation where readable text is converted into unreadable secure text. It’s simple to perform and efficiently executed but is extremely difficult or irreversible. This makes it a one-way hash function and differentiates it from the encryption protocol which is a two-way function and can be reversed.
In hashing, the cryptographic function will take plain, readable text and generate a string of unique data randomly. It can include many variables such as numbers or text as seen in the above example.
For example, let’s take a password you use for accessing your bank account. The banks will securely store your passwords after implementing a one-way hashing function. Now, when you try to access your account by entering the password, it’s matched with the stored hash value. If it matches, you’ll get authorization from the bank to use your account.
Simply put, a hashing function in cryptography is used for data authorization to grant users access without knowing the content. Primarily cryptographic hashing is used in securing databases, storing passwords, and protecting the credentials of code signing certificates. They are saved as hash values to make your sensitive data more secure.
Moreover, the cryptographic hash function creates a barrier for potential attackers. Even if the hackers get access to the database and your hashing values, they cannot reverse it to get the actual password. However, some cryptographic functions like SHA-1 are easier to crack than others like SHA-2 or bcrypt.
Properties of Strong Cryptographic Hash Function
Here are a few key properties that make hashing function in cryptography strong:
- Determinism: A hash value should always be deterministic, meaning the output size of the hash value should be the same regardless of the input size. For instance, a hash output for each unique input of 10 and 20-word messages will have a fixed length digest.
- Collision Resistant: When two cryptographic hash values are identical for unique input messages, it results in a collision. This simply means your hashing algorithm is broken and not safe as anyone can create the fake hash and match it with a genuine one. A good hash function should always be collision-proof.
- One-Way Hash Function: The concept of a strong hash algorithm is based on the one-way hash function, which doesn’t support reversing the hash value to get the original input.
- Hash Speed: Ideally, we want a quicker algorithm to compute hash values. However, the hash speed is subjective and depends on what context we are using it for. Faster cryptographic hashing is better for website connection while slower ones are better for password hashing.
Features of Cryptographic Hash Function
Some typical features of cryptographic hashing include:
- The hashing algorithm is used to convert the input data of arbitrary length to a fixed length.
- This hash value is often much smaller than the input data and that’s why it’s also called a compression function.
- The whole process is known as hashing where large data is represented with smaller values also referred to as digest.
- Hash functions generally create values between 160 to 512 bits.
- In comparison to encryption symmetric, hash functions are computationally faster.
Applications of Cryptographic Hashing
Here are a few applications of the hash function in cryptography:
- Secure Password Storage: Using hashing, you can store your passwords securely in a hash rather than in plain text. The hash values or digest of your password will be stored in the hash table.
- Password Verification: Another use of hashing function is to verify the authenticity of the user. Every time someone logs in to a system or account, it’ll run a verification to check the typed password matches with the hashed password.
- Data Integrity Check: Hashing ensures users about the data integrity and provides assurance that it’s not modified. Thus, users can be sure that the data is original and intact.
Wrapping Up
Cryptographic hash functions are widely used for safeguarding passwords and other sensitive information. In this article, we learned what a cryptographic hash function is and how it works.
We have also learned what properties a one-way hash function should have along with features and applications. So, we hope you have gained an in-depth understanding about the cryptographic hash function.