I've just seen this news on my facebook feed. Anyone else? If this is true and working, bitcoin will be safe from quantum computers and there's basically nothing else that could bring bitcoin down. Thoughts?
http://www.sciencealert.com/scientists-claim-to-have-invented-the-world-s-first-quantum-proof-blockchain
Cornell University Library:
https://arxiv.org/abs/1705.09258v1
http://www.sciencealert.com/scientists-claim-to-have-invented-the-world-s-first-quantum-proof-blockchain
Cornell University Library:
https://arxiv.org/abs/1705.09258v1
In fact, this was already foreseen in bitcoin, and in fact in all crypto that has hashed public keys:
https://en.bitcoin.it/wiki/Quantum_computing_and_Bitcoin
Essentially, only used once-addresses are safe, and the trick is to use the public key that is hashed, as the secret key of a hash-based signature scheme (one-shot, but you only need one-shot). Lamport signatures are a possibility.
(because the public key is now the secret key, this explains why an address can only be used once: if you use it twice, your public key is exposed).
It is old news, because already in 2013, a certain Vitalik Butterin explained this:
https://bitcoinmagazine.com/articles/bitcoin-is-not-quantum-safe-and-how-we-can-fix-1375242150/