The NSA designed the SHA-256 and it's variants and some people suspect that they added a backdoor.
Backdoors
Backdoors are hidden ways they can use to break the encryption. However, nobody has since found a security flaw or backdoor.
Today, 20 years after its initial release SHA-256 is considered safe.
Cryptographic Hashes
Cryptographic hashes are needed for blockchain encryption.
Those need to have five properties:
- They need to be deterministic and fast.
- They must only work in one way.
- Reverse engineering must be infeasibly hard.
- Small changes to the input must change the output massively.
& - Collisions must be super rare.
Note: This content neither represents financial, legal or tax advice.