Now that we know what hashes are, we can explain how they are used in SSL Certificates. The hashes you have seen thus far are NOT SHA hashes of any type. Note: To make it easier to read and comprehend this article I am using an example data string and hashing algorithm that is significantly shorter than what would actually be used in practice. Unique meaning that two different pieces of data can never produce the same hash – the next section explains why this is so important.
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Irreversible meaning that if you only had the hash you couldn’t use that to figure out what the original piece of data was, therefore allowing the original data to remain secure and unknown. If you only take away one thing from this section, it should be: cryptographic hash algorithms produce irreversible and unique hashes. SHA stands for Secure Hash Algorithm – its name gives away its purpose – it’s for cryptographic security. There are hundreds of hashing algorithms out there and they all have specific purposes – some are optimized for certain types of data, others are for speed, security, etc.įor the sake of today’s discussion, all we care about are the SHA algorithms. Hashing algorithms are used in all sorts of ways – they are used for storing passwords, in computer vison, in databases, etc. Any computer in the world that understands the hashing algorithm you have chosen can locally compute the hash of our example sentence and get the same answer. One of the key properties of hashing algorithms is determinism. It is easier for the computer to first compute a hash and then compare the values than it would be to compare the original files. Hashes are convenient for situations where computers may want to identify, compare, or otherwise run calculations against files and strings of data.
![hashtab compare hashtab compare](https://rubenalamina.mx/wp-content/uploads/2016/08/hashtab.png)
Sometimes hashing is referred to as one-way encryption. This result is known as a hash or a hash value. …and ran it through a specific hashing algorithm known as CRC32 we would get: “07606bb6” So, for example, if we took the sentence… “The Quick Brown Fox Jumps Over The Lazy Dog” These are critical concepts to understand before you’ll be able to follow what SHA-1 and SHA-2 are.Ī hashing algorithm is a mathematical function that condenses data to a fixed size. If you have heard about “SHA” in its many forms, but are not totally sure what it’s an acronym for or why it’s important, we’re going to try to shine a little bit of light on that here today.īefore we can get to SHA itself though, we need to run through what a hash is, and then we’ll get into how SSL certificates use hashes to form digital signatures. In Everything Encryption SHA-1, SHA-2, SHA-256, SHA-384 – What does it all mean!!