Sigh. Blockchain is a buzzword.
As currently implemented, most if not all blockchains have numerous inherent security flaws and other issues. For one example, most blockchains use standard private/public key cryptography based on the difficulty of factoring large composite numbers. The public keys are published in the chain. Quantum computing is going to render that completely useless from a security perspective — in fact already has for smaller sized keys. For another example, validating a transaction using most blockchain implementations takes far too long to be viable for point of sale and other transactions.
Could go on and on about these and other problems, but why bother? Most people will just buy into the buzz...
I’m mixing apples and oranges a bit here, but Blockchain is really just a digital ledger linked by a cryptographic hash function. It’s math.
And the Gaussian Copula is just a probability distribution. It’s also just math:
https://en.wikipedia.org/wiki/Copula_(probability_theory)#Gaussian_copula
That particular bit of math (which also contained some inherent flaws) led to the economic meltdown in 2008. I have no way of knowing if the flaws in Blockchain could do something similar. But a lot of people use complex math that they think they understand. But they don’t understand them enough.
Interesting times.
While there is some truth to this, its not entirely accurate.
For one example, most blockchains use standard private/public key cryptography based on the difficulty of factoring large composite numbers. The public keys are published in the chain. Quantum computing is going to render that completely useless from a security perspective — in fact already has for smaller sized keys.
Public keys are only published when coins are spent. The public to private key computing would have to happen very fast in order to have a chance of spending the funds before the legitimate transaction propagates.
In any case, all internet security is based on the same type of cryptographic system. There are already known quantum safe systems and everything on the internet will migrate to those systems in the future.
For another example, validating a transaction using most blockchain implementations takes far too long to be viable for point of sale and other transactions.
This may be nit picky, but transactions propagate and are validated on the network within seconds. It is true that it takes longer to secure a transaction in the blockchain, which may take from 10 to 60 minutes. But once that happens, the merchant has the funds. With the credit/debit system it may be days to weeks before the merchant is certain that they have the funds.
and it costs too much. These are part of the reasons that Bitcoin has lost so much value. It is unable to beat the transaction cost of a simple credit card and it takes too long.
I'd worry less about the factoring issues of small public exponents than about the other implementation issues. The most recent factoring record that I was able to find was 56153, which was reported in 2014. My desktop computer can factor 45219326826295417525240588747 in .167 seconds, and it is 7 years old.