SHA hash functions facts for kids

In the world of secret codes, Secure Hashing Algorithms (often called SHA) are a group of special math tools. They were created by a government group called the National Institute of Standards and Technology (NIST). These tools take any information you give them and turn it into a short, unique code. Think of this code as a "digital fingerprint" for the information.

The length of this digital fingerprint changes depending on which SHA tool you use. These fingerprints are usually shown using a special number system called hexadecimal.

What are Secure Hashing Algorithms?

Secure Hashing Algorithms are like digital fingerprint makers. They take any kind of data, like a message or a file, and create a short, fixed-length code from it. This code is called a "hash" or "digital fingerprint."

It's very hard to find two different pieces of data that create the exact same hash. This makes them useful for checking if information has been changed. If even one tiny part of the original data is different, the hash will change completely.

The SHA Family Tree

Over the years, different versions of the Secure Hashing Algorithm have been released. Each new version tried to be stronger and safer than the last.

SHA-0: The First Try

SHA-0 was the very first Secure Hashing Algorithm. It came out in 1993. However, people quickly found problems with it. It wasn't safe enough to use for important things. Because of this, it was soon replaced by a newer version.

SHA-1: The Next Step

SHA-1 was the first official name for the Secure Hashing Algorithm. It was released after the weaknesses in SHA-0 were found. The National Security Agency (NSA), a government agency, helped create it. For a while, SHA-1 was used a lot. But over time, experts also found weaknesses in SHA-1. It became clear that it was no longer safe enough for protecting very important information.

SHA-2: Strong and Popular

SHA-2 is one of the most widely used types of SHA today. It offers more choices for how long the digital fingerprint will be. You can choose lengths like 256 bits or 512 bits. These versions are often called SHA-256 and SHA-512. The National Security Agency also helped develop SHA-2. It is considered much stronger and safer than SHA-0 or SHA-1.

SHA-3: The Newest Version

SHA-3 is the latest type of Secure Hashing Algorithm. It is also known by its original name, Keccak. It was created by a team of four people: Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche. SHA-3 was chosen after a big competition held by the NIST. This competition looked for the best new hashing algorithm. SHA-3 is designed to be very secure and is a great option for future digital safety.