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Comment by barnbuilder | Hacker News Reader

> For Bitcoin, the most popular one, on the order of 100.000.000.000.000.000.000 of hashes get calculated to mine a single block, multiple trillion per second. Within ten minutes, only a single one of those 100.000.000.000.000.000.000 hashes is actually used, depending entirely on luck. The rest are thrown away entirely. They do not form part of the final hash or anything else, the energy spent on them is lost.

All of those hashes and the energy required to generate them represent work that would need to be redone (along with all subsequent work) by an attacker in order to double-spend the transactions in that block. It's the most efficient way to use energy for security that there is.

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False. The regular banking and payment card system is far more energy efficient while maintaining a higher level of security.

The banking system has zero security for you as an individual. The DB admins though? They do enjoy some security. (Still not as much as Bitcoin, having central points of failure.)

False. Bank systems are highly secure. If I suffer a loss due to hacking or identity theft then I can get my money back.

Have you ever had a fraudulent credit card transaction? I've had at least 5 over the last 30 years including some for over $2,000. I call the credit card company, tell them this wasn't me, the charge gets removed, they cancel my card and send me another in 3 days. In the last 10 years their fraud monitoring has gotten good enough that they see something suspicious and block the transaction. Then they email, text, and call asking to verify if this was really me.

Not really, it's secured by Proof of Violence/Imprisonment in partnership with the country's government. And the government spends a lot more energy doing that than bitcoin does

We need the state monopoly on violence in order to maintain an orderly society, regardless of which monetary system we use. The energy used by law enforcement to secure the financial system is a tiny fraction of the total, and switching from fiat currency to cryptocurrency wouldn't reduce that energy use at all.

By this metric, asymmetric cryptography is billions of times more efficient, as an attacker has to do tons of work, but I need to do very little.

So no, it is incredibly inefficient compared to many other forms of security.

I think you missed the double-spend part of OP's response.

To be fair, you are comparing a cryptographic algorithm to a consensus (leader election) algorithm. Not exactly apples to apples

Why are you comparing two trusted parties' communication against random amount of counterparty transactions?

When it comes to cryptocurrency, suddenly comment quality goes down the floor in HN.

Proof of work has the same asymmetry: producing high PoW is very costly, but verifying PoW is trivial. That's very much the essence of PoW.

How does asymmetric cryptography solve the Byzantine General's problem again? I'm all ears.

"More efficient" doesn't form a complete sentence, you've elided "more efficient at".

They are not thrown away. They directly represent the security/reliability of the consensus model. That’s the whole point.

> It's the most efficient way to use energy for security that there is.

After a halving, when BTC pays half as much to miners, does it get twice as efficient? Or half as secure?

Given a set market value of BTC, halving the block reward halves the consensus security.

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