SHA-1, SHA-2 & SHA-256 – Know the Difference
Before we get into the details of SHA, let’s first understand hash as it’s one of the essential concepts which must be clear before you try to understand what SHA-1, SHA-2, and SHA-256 are.
Let’s understand the Hash.
What is a Hash Algorithm?
The jay, pig, fox, zebra, and my wolves quack!“
and once we run a specific hashing algorithm, let’s say CRC32 we get the below result:
This above result “065bf922” is known as a hash value or hash.
Furthermore, it’s also known as one-way encryption, though it’s not always true. As said, whenever you hash any data, it gives the output as a hash value, which is of fixed length. But, that’s also the fact that different data will produce different hash values as a result. Even the smallest change to data will produce a different hash value.
Let’s look at it by making the small change from the above example:
The jay, Pig, fox, zebra and my wolves quack!“
As expected, this time result is different:
The essential properties of the hashing algorithm are determinism. Because, no matter which computer you select, your or any other and if you compute the hash example which we used above, will give you the same result. Also, Hashing is used for many things, such as password storage, database, and many more.
Now, let’s get into SHA and the difference between the different versions.
What is SHA?
SHA called SHA Hash Algorithms offers a way to the computer to quickly authenticate and decrypt information shared by the users. For example, the SSL/TLS certificate used by the website we surf relies upon this SHA algorithm to quickly navigate us to the right place instead of being trapped by malicious hackers or middlemen. SHA algorithm creates a unique hash of an SSL Certificate along with its signature, which protects users like you and me from giving away private and sensitive information to cybercrooks.
Let’s learn how does SHA works and why it’s crucial to make use of the latest versions.
Different Versions of SHA
Here’s the Role of the Hash Algorithm in SSL/TLS
Let’s see with an example of the RSA signature.
Here, the signature hashes the data which has to be signed, “encrypted” using the signer’s private key.
What’s the Difference Among SHA-1, SHA-2, and SHA-256?
The significant difference between the two SHA-1 and SHA-2 is about the hash length. Here, SHA-1 is a basic version of the hashing function, and it’s close to the MD5 in nature, which means SHA-1 has a shorter code resulting in less possibility for unique combinations, whereas SHA-2 or SHA-256 makes a more extended code and offers more complex hash.
Moreover, SHA-1, developed by the US government, offers 20 bytes (160-bit) hash values, which are represented by the hexadecimal string value of 40-digits. On the other hand, SHA-2 was also developed by the US government, especially the NSA, and it’s a family of algorithms that contains six different hash functions that provide hash/digest values of varying lengths, namely: 224, 256, 384 or 512. In other words, SHA-2 is a different range of hash functions, which includes SHA-256. Lastly, by 2015, due to vulnerability issues of SHA-1, it was phased out, and from 2016 onwards, it even became a compulsion to make use of SHA-2 for all the newly issued SSL/TLS certificates.
Moreover, it’s evident that SHA-1 is less secured and phased out version, whereas SHA-256 is widely used in today’s date. Also, SHA-256 is one of the variants of SHA-2 cryptographic hash functions family, which is mostly used in today’s date, including blockchain and SSL/TLS certificates.