Bitcoin Forum

This is purely speculative but with the price of bitcoin being heavily dependent on mining difficulty, what do you see in the future for bitcoin with quantum computing? Will everything convert to a Proof of Stake system? Thoughts?

You've got that backwards.

Mining difficulty is heavily dependent on the price of bitcoin.


Greater security.


Absolutely not.

I try not to think about it, but I still think that's too far off to speculate now.  It certainly could have a drastic effect in the future and will need to be dealt with delicately.. it sort of raises the debate if bitcoin's use case or its cost to create is more weighted when looking at its current price.   As far as proof of stake is concerned, I'm really not sure.  You could argue that proof of work or proof of stake is becoming too centralized and the cons and pros of each cancel each other out, but at least proof of stake is more environmentally friendly.  Speculation for the price on bitcoin in the short time is there will be a halvening in 2020.  I'm not sure of exact figures but this will take the difficulty up to about 12-15,000$ on avg to mine one bitcoin.. seems like pretty bullish for price action to me.  

Here's an article about the last halvening.. the article says it didn't really have much effect at the time, but its pretty easy to see where it went shortly after in price:

https://bitcoinmagazine.com/articles/how-bitcoin-s-second-halving-came-and-went-and-not-much-happened-1468856719/

The difficult could drop back to Cpu levels if the price crashed to 1 penny.  quite frankly, there is a lot of speculation about quantum computing right now.  I don't think quantum computing will ever exist and it is still only a theory.

If I remember correctly the National University of Singapore released a quantum computers paper that argued that the danger is real and imminent for any sort of cryptography.

“The elliptic curve signature scheme used by Bitcoin is much more at risk, and could be completely broken by a quantum computer as early as 2027,” say Aggarwal and co.

It will be interesting to see if this becomes a major problem.

If quantum computing can crack bitcoin i don't think it will be used for that purpose. Imagine all the government security codes it could break, electronic bank vaults, bitcoin is nothing compared to what a real quantum computer could do. The cyber world will have bigger problems to worry about.

Hey, don't worry about it, Bitcoin will be already completely dead by that time... we'll never find out.

1. No working quantum computer has been built yet.
2. A Quantum computer can reverse a public key. i.e calculate private key from public key. That is the end of the security of BTC
3. Quantum computers have massive computational power so they could get more than 51% of computational power of BTC network easily which may lead to spent same BTC twice. i.e breakdown of the system.

POS can secure blockchain only from 3rd fact in the list.


However even POS is vulnerable to quantum computers. See here - https://bitcoinmagazine.com/articles/quantum-computing-and-building-resistance-proof-stake/

Conclusion

If someone build a quantum computer it will be the end of BTC. Only Quantum proof cryptography based cryptocurrencies will be safe.

Quantum Computer? quantum computers are very difficult to realize but with the development of any technology can occur. It may also have an effect on bitcoin. With the power of quantum computers it can hack the BTC security system. And BTC should be upgraded its security system.

A lot has been going on in terms of securing cryptocurrencies against quantum computers. For example, the development of the Quantum Resistant Ledger (QRL), which is a public blockchain ledger that uses post-quantum secure signature scheme known as the Extended Merkle Signature Scheme called XMSS to secure blockchains. QRL uses a Proof of Stake algorithm that uses hash-chains and hash-based pseudo random number functions and does not rely on conventional signatures.