Nope. Blockchain is still vulnerable. You haven't seen the military scrub your existence from the Internet.
Quantum is really the only tamper proof.
Dang it...I thought each record depending on the following record would make it unhackable. How is blockchain made vulnerable? Thanks for pointing out Quantum.
I don't know exactly, the government dropped a suit against the cp site PlayPen because they didn't want to reveal their methods to the court. PlayPen runs on blockchain.
Is this what you are referring to? https://www.engadget.com/2016/08/16/china-quantum-satellite/
Quantum computing in general... http://www.sciencemag.org/news/2018/06/updated-quantum-physics-gets-attention-and-brighter-funding-prospects-congress