Quantum Cryptonomics & Known Vulnerabilities in the Blockchain
Now let's not get carried away with superpositions & entanglements, but two of the most important technological advancements currently underway are the advent of quantum tech, along with the transitioning of the global financial systems towards digital crypto assets, primarily blockchain & smart contracts.
With new payment platforms comes new problems that have been extensively researched, and with the introduction of quantum tech which will have the ability to compromise the foundations of blockchain, there are a couple known vulnerabilities that can lead to quantum failure. Quantum computing has become the foremost as having potential to compromise essential elements of present day crypto techniques such as public key cryptography and digital signatures. This has a few concerns with blockchain, there are a few misunderstandings on how this could occur.
Quantum Failure could manifest in two ways, the first being a purely monetary phenomenon that reduces the value of the native cryptocurrency, while keeping the integrity of the ledger intact and second as an accounting issue that undermines the integrity of the ledger making blockchain along with cryptocurrency worthless. Quantum failure could allow an attacker to solve a computational problem faster than other miners thus earning the majority of the block rewards which implies that mining can produce coins faster than the current 6.25 coins every 10 minutes (potentially until all bitcoins have been produced) which would increase the rate of monetary expansion known as Grover-expansion.
While not destroying the blockchain if done on a small scale would just add legitimate entries at a faster pace. With the difficulty constantly being adjusted, the attacker could earn a maximum of 12,600 bitcoin before the parameter is adjusted. Once adjusted the attacker would still be the fastest to solve the now more difficulty. Now if done on a larger scale, known as the 51% attack which occurs when the pool has over half the computational power of the network and dominates the blockchain.
This would allow it to perform a double spend attack by performing a spend transaction on one branch of the blockchain while growing a parallel branch where that spend record is missing. With the computational power above the majority, the parallel chain will likely grow larger than the original and trusted nodes will adopt it, hence allowing for the second spend at no additional cost. The second manner in which a quantum attacker can exploit the blockchain is by falsifying digital signatures and stealing existing tokens. This would cause panic selling and this kind of attack is referred to as a Shor-attack by rendering the blockchain entries unreliable. While much different than Grover-expansion, both attacks would be launched simultaneously resulting in a Grover-Shor attack. The 2 major threats enabled by a Shor attack would be firstly a fast steal. With a legitimate transaction being added to the network but before it has been verifies (within 10 minutes) the attacker can learn the private key of the sender from the public key. Then the attacker broadcasting a new transaction from the same sender's address to themselves. If the attacker offers a higher transaction fee, that transaction will take priority in the queue and will be verified first, meaning successful and unstoppable theft.
The second is the recovery of lost Bitcoin via exposed public keys attached to the private key. Which is estimated upwards of 33% Bitcoin allocated so far are dormant public addresses from owners who have may lost the private keys and are unable to access the coins thus making them vulnerable to a quantum attack. A Shor-attack would allow the threat actor to learn the private key & sweep these coins. Which would clearly increase available circulating supply & devalue the currency if sold quickly. Quantum hackers could falsify blocks being added to a blockchain & double spend tokens on any blockchain depending on the blockchain's features. This would result in monetary inflation, with indicators in place by some big name's in blockchain to ensure this is not happening and they would be able to detect quantum failure right away.
With many early abandoned public keys that are prone to private key attacks, it's best to look into securing your digital assets with services such as Curv.co or reliable Hot/cold wallet setups and not sending from an address that would divulge your public key corresponding with your private key, this is why many prefer using actual secure cryptocurrency like Monero. Check out the full research carried on blockchain quantum failure (link) for more details on quantum crypto economics.
What is not mentioned may be some of the known lightning node network vulnerabilities this makes it even more of a concern even if they aren't as severe as the concern of quantum failure on them would essentially pose a quicker standstill. Griefing could allow an attacker to free bitcoin deposited in a lightning payment channel by spamming that channel with micropayments, devs seem to have a firewall solution called "circuitbreaker" which could allow node operators to set limits on how many payments and channels a peer can open with their node.
A Flood & Loot vulnerability would be bad news for a victim that could actually lose funds from this kind of attack which is easier to execute than others, meanwhile devs have recently pushed anchor channel update which allows lightning users to change fees more dynamically when closing a channel, will go a long way towards a fix.
Meanwhile a time-dilation eclipse is a serious attack that would require the attacker to operate hundreds of lightning nodes to succesfully eclipse a victim, there isn't a single solution to deploy on the lightning protocol since this attack also relies on manipulation of on-chain data.
And another concern for the lightning node network would be pinning where an attacker can trick a victim into closing their channels improperly thus steal individual transactions. A new update for so called anchor outputs will mitigate this kind of attack.
To read more about Lightning node vulnerabilities (link) which have not been exploited yet, with the advancement in quantum technology it's good that research is being thoroughly done on this and while there is constant blockchain analysis at work, we can be sure there are big company's that will not tolerate any ruckus on the blockchain so we can assure assets are secure.