SHA
SHA stands for Secure Hash Algorithm. It is a way to encode data with an asymmetric data encoding function. There are many implementations of this class of algorithms, generally known as SHA-0,SHA-1,SHA-2,SHA-3.
A Shattered SHA-1 Function
It is public knowledge that Google had cracked SHA-1 and presented a website called:shattered.io to disclose their findings. You can even test if your document encoded using SHA-1 has name collisions or not. Name collision is a situation where names chosen by Secure Hash Algorithms (SHA) to represent a specific data object maybe shared by two different data objects. This name collision problem could allow one to submit a fake document or fake data object that has the same digital digest (the name), therefore confound the authenticity of information. An example of name collision can be found on shattered.io[1].
Particularly useful tutorial
It would be good to read up on this website[2].
References
- ↑ Stevens, Marc; Bursztein, Elie; Karpman, Pierre; Albertini, Ange; Markov, Yarik (2017). The first collision for full SHA-1 (PDF). local page: Shattered.io.
- ↑ An Illustrative Guide to Cryptographic Hashes by Steve Friedl