You've probably heard this term before in relation to cryptocurrencies, but you may not know how it started and what exactly it means 🧵👇

SHA 256 was published in 2001 by both the NSA (National Security Agency) and NIST (National Institute of Standards and Technology).

SHA 256 is part of the SHA 2 family, which includes SHA 224, SHA 512, and many other algorithms.

The SHA 2 family was a successor to SHA 1, which had become vulnerable to brute force attacks.

SHA stands for Secure Hash Algorithm.

A secure hash algorithm takes plaintext as a string of bits of arbitrary length and converts it into a "hash" of fixed length.

256 stands for 256 bits (which is equal to 32 bytes).

This means that no matter the length of the input data, the hash that is output will always be 256 bits.

With Bitcoin, the data that is hashed is called a 'header.'

The header of a block contains information about the preceding block.

SHA 256 is meant to be 'irreversible.'

This means that, given the hash, you should not be able to discover the original data.

The newest Secure Hash Algorithm is SHA 3

It was published by NIST in 2015, but since no significant attack has been demonstrated against the SHA 2 family, it was not meant to completely replace it.

It has a different structure than SHA 1 and SHA 2. With SHA 3, the hash size is arbitrary instead of fixed.

Although SHA 256 is still widely used, SHA 3 is considered by many to be more secure.

Since there is a concern that SHA 256 may be vulnerable to quantum computers, other algorithms may be necessary as the technology improves.

Thanks to everyone who made it this far!

Please like, recast, and comment if you liked the thread!

You've probably heard this term before in relation to cryptocurrencies, but you may not know how it started and what exactly it means 🧵👇

SHA 256 was published in 2001 by both the NSA (National Security Agency) and NIST (National Institute of Standards and Technology).

SHA 256 is part of the SHA 2 family, which includes SHA 224, SHA 512, and many other algorithms.

The SHA 2 family was a successor to SHA 1, which had become vulnerable to brute force attacks.

SHA stands for Secure Hash Algorithm.

A secure hash algorithm takes plaintext as a string of bits of arbitrary length and converts it into a "hash" of fixed length.

256 stands for 256 bits (which is equal to 32 bytes).

This means that no matter the length of the input data, the hash that is output will always be 256 bits.

With Bitcoin, the data that is hashed is called a 'header.'

The header of a block contains information about the preceding block.

SHA 256 is meant to be 'irreversible.'

This means that, given the hash, you should not be able to discover the original data.

The newest Secure Hash Algorithm is SHA 3

It was published by NIST in 2015, but since no significant attack has been demonstrated against the SHA 2 family, it was not meant to completely replace it.

It has a different structure than SHA 1 and SHA 2. With SHA 3, the hash size is arbitrary instead of fixed.

Although SHA 256 is still widely used, SHA 3 is considered by many to be more secure.

Since there is a concern that SHA 256 may be vulnerable to quantum computers, other algorithms may be necessary as the technology improves.

Thanks to everyone who made it this far!

Please like, recast, and comment if you liked the thread!