SHA-2 is an open algorithm and it uses as it is constants sequential prime cube roots as a form of "nothing up my sleeve numbers". For someone to find a weakness or backdoor in SHA would be the equivalent of the nobel prize in cryptography. Everyone who is anyone in the cryptography community has looked at SHA. Not just everyone with a higher degree in mathematics, computer science, or cryptography in the last 20 years but foreign intelligence agencies and major financial institutions. Nobody has found a flaw. Not even an academical one.
To believe the the NSA has broken SHA-2 would be to believe that the NSA found something the entire rest of the world combined hasn't found for twenty years. For the record SHA-3 is not yet approved for classified networks in the US, only SHA-2 is. So that would mean the NSA is endangering national security by not declaring SHA-2 degraded.
Anything is possible but occam's razor and all that.
Well said. There are many more cryptographic experts in the world than at the NSA. It's not a secret algorithm that's controlled by the NSA. It's in the public domain. Anyone can examine it. If you still think the NSA has a secret back door, then there's a good possibility you're a delusional paranoid shit head.
A) No need to be vulgar B) it is reason to double check that our implementation of SHA-256 is secure. There could be ways that different secure SHA-256 systems could become vulnerable, like for example- I'm now tempted to think Androids Random Number problem might have been deliberate. It exposed private keys, but maybe it's exposed so much more that the NSA has found valuable.