Difference Between SHA-1 and SHA-2 Hash Algorithms

All You need to know about SHA-1, SHA-2 (SHA-224, SHA-256, SHA-384, SHA-512) Hashing Algorithms!

Data is the new currency! Modern digital transformations are fuelled by data exchange and access to enormous resources. With more than 4 billion effective internet users globally, massive amounts of data are exchanged every day.

So, securing the data has become one of the essential parts of any business looking to leverage digital transformations, and this is where hashing algorithms can help. They create hash values which are the string of values through which you can identify the data without reading the content inside. It is like reading an envelope without a letter inside.

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Why is hashing necessary now?

Data theft has increased over the years, causing massive business losses. According to a report, cybercrimes have incurred damages worth $6 trillion in 2021. Hashing algorithms can help you avoid such scenarios by allowing you to hash data files avoiding exposures.

You might not be using it directly as hash values are used in SSL certificates and digital signatures. So, here we will discuss hashing algorithms, hash values, and different variants like SHA-1 and others. But, first, let us start with what a hash value is.

What is a Hash?

Hashes are a string of unique alphanumeric values that help identify similarities between two files or datasets without accessing their contents. It results as an output of hash algorithms like SHA (Secure Hash Algorithm) or MD5(Message Digest 5).

These hashing algorithms produce a unique and fixed-length string of values for a data or “message.” So, for example, every file in a device or PC is just data that will be in a binary form like “1001010101010.”

A hashing algorithm runs complex mathematical calculations on such data to generate a string of values. These values are also known as the hash, which is used for digital signatures and SSL certificates.

Hash values have been used as a core technology for several antivirus solutions as they can easily detect malicious files without accessing the file’s contents. However, with modern technologies, hackers are getting smarter; these hash values do not offer that protection for antivirus solutions.

However, for use cases like code signing certificates and SSL certification, hash values are extensively used. One of the most common usages of hash values is in threat hunting or malware sampling. Cybersecurity researchers, SOC teams, and reverse engineers use hash values to detect malware or as indicators for threat analysis.

Benefits of Hash Values

  • Identification of threats inside the system through malicious file detection
  • Scanning the anomaly across systems becomes easy with hash values
  • Hashing allows easier identification of data than finding it among table or column arrays.
  • Hashed passwords are one of the safest as they cannot be reused or even exposed to hacking.
  • Hashing allows users to know whether a file or website they access is genuine or not.

In the modern era of SSL certificates and digital signatures that help secure mobile applications, hashing algorithms have also seen massive acceptance. One such algorithm that has been popular is SHA.

Let us understand what SHA is and why it is so popular!

What is SHA?

SHA or Secure Hashing Algorithm is a modified version of Message Digest-5(MD5). It enables hashing of data and files for security. SSL certificates and digital signatures also use SHA for hashing the information. However, it shortens the input information into a smaller form that is not easily understood and is hard to modify through bitwise operations, adding modulations or functions.

What makes SHA a reliable security option is its ability to secure information that can only be exposed to hacking by brute force. This is because hashing in SHA does not allow decoding of the information, unlike an encryption process.

As you can see in the above image, A single change in the message or data generates a new hash value. So, if two similar kinds of data are hashed with a smaller difference, like, say, a capital letter, then there will be two different hash values.

There are several SHA algorithms like SHA-1, SHA-2, SHA-224, SHA-256, SHA-384, and SHA-512. However, before we discuss diverse types of SHA, let us discuss the usage of SHA.

Usage of SHA

Secure hashing algorithms are primarily used to sign digital signatures for mobile applications and software. This is a process where the application developers can ensure that the users download and install the app through a digital signature avoiding any security issue.

It is also used for SSH or Secure Shell, a cryptographic network protocol used for network services hosted on an unsecured network. SHA is also used for Secure/ Multipurpose Internet Mail Extensions or S-MiME and IPsec. It helps in hashing the password so that the server will only need to remember the hashes rather than passwords. So, if an attacker decides to expose your passwords, hash values will be able to protect them.

Now that we know all about SHA let us discuss several types of hashing algorithms.

What Is SHA-1 and SHA-2 (SHA-224, SHA-256, SHA-384, SHA-512)

The SHA-1 hash is generated through the condensed representation of a message or data file. It is a hashing algorithm that produces a 160-bit output that can be used to input the Digital Signature Algorithm (DSA). This is then converted into a signature to be verified for secure access to data files or applications.

Signing the message digest or data file rather than the contents can improve the entire process’s efficiency as it also helps with memory optimization. The hash values are compressed than the original message making it easy to manage the memory. However, for the verification process, the user needs to use the same algorithm that the creator of the digital signature used.

SHA-1 has been popular but is no longer considered secure, and the reason is simple hash modifications. With advanced hacking practices, there was a need for a more reliable version of the hashing algorithm. This was when SHA-2 came into existence, and since then, there has been a discussion about SHA-1 vs SHA-2.

So, let us understand SHA-1 vs SHA-2 in brief!

SHA-1 vs SHA-2 – What is the Difference

SHA-1 was designed to be unbreakable where it was assumed that there is no possibility of finding the same message digest or hash value for two different message digests. However, this was changed with the addition of a modular function by hackers that exposed the weakness of SHA-1.

At the same time, SHA-2 is a hashing algorithm developed by the US Government along with six different hash values ranging from 224,256,384 and 512. Furthermore, in a notification published by NSA, FIPS PUB 180-2, different variants of the SHA were announced.

These variants of the SHA algorithms were SHA-1, SHA-2, SHA-224, SHA-256, SHA-384, SHA-512. All these variants have been modified versions of the SHA-1 to improve the security and hashing function.

For example, SHA-256 and SHA-512 are hash functions that are computed in 32-bit and 64-bit values. However, the virtual structure is the same with different shift amounts and additive constants.

Similarly, SHA-224 and SHA-384 are the compressed versions 256 and 512 variants with different initial values. Now that we have a basic understanding of these variants, let us have a side-by-side comparison of SHA-1 vs SHA-2.

It is a cryptographic hashing function developed by the National Security Agency in the US to replace the SHA-0 algorithm. NSA developed it to replace the SHA-1 algorithm.
It was published in 1995 Published in 2001
The core structure is based on Merkle–Damgard construction and is less secure than SHA-2. Its core structure is based on Merkle–Damgard structure with Davies–Meyer compression function. and is far more secure than SHA-1
Hash is generated in a smaller size with 160-bit based hashing Hash is generated in a larger size with 256-bit based hashing
Not used these days most often Immensely popular in usage for DSA and SSL certificates

So, the critical discussion here is whether you need to upgrade your security systems to SHA-2? Well, the answer is yes!

Why Do You Need to Upgrade at SHA-2?

To begin with, every major browser on the internet supports SHA-2 based SSL certificates and DSA for secure access to websites or data. So, upgrading your websites to SHA-2 based certificate is essential. If you avoid it most of the time, these browsers show an error message or do not allow browsing on websites with SHA-1 certificates.

Another important aspect is security; SHA-1 essentially has been weak due to modular function attacks where hackers tend to change the hash values. However, this is not the case with SHA-2 making it a reliable solution for your websites.

It is also important to understand that the transition from SHA-1 to SHA-2 is not easy, and you need proper planning. First, you will have to create an SHA-2 PKI (Public Key Infrastructure).

  • Training the entire team on the migration towards SHA-2 and helping them understand the process.
  • Ensuring proper documentation to avoid any issues during the migration process
  • Storing all the critical hash and digital certificates used across the system
  • Determining the applications and devices that need to be migrated to certificate with the SHA-2 algorithm.
  • Figuring out the vital aspects like key sizes, operational caveats, vendor selection, and testing needs
  • Determining of PKI components for the migration to SHA-2
  • Creation of a migration plan along with a fallback plan to counter the critical failure.
  • Proof of concept testing and risk assessment
  • Risk strategy building and acceptance of risks for decision making
  • Execution of the migration plan inside the production environment
  • Testing and feedback integrations
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SHA-2 is far more secure than the SHA-1, and there is no denying that you need to upgrade your systems to it. But, first, you need to assess the applications and devices that you want to upgrade.

If their operating systems or specific components do not support SHA-2, you have to face a fallback. So, the best practice is to leverage a vendor that offers advanced SHA-2 based security solutions without worrying about the upgrades.

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