[Cryptography] One Bitcoin Transaction Now Uses as Much Energy as Your House in a Week

Benjamin Kreuter brk7bx at virginia.edu
Mon Nov 6 17:21:23 EST 2017

On Mon, 2017-11-06 at 12:28 -0800, Jameson Lopp wrote:
> I don't think it's a useful abstraction, but rather a distraction.
> Transactions don't "use" mining energy - this is a skewed perspective
> of how Bitcoin's thermodynamic security operates.

For a payment system, the energy needed to process a payment is the
metric that matters; the simple way to compute this is to divide the
total energy consumption of the system in a given time period by the
number of transactions processed in that period.

> If you really want to approach this from a "per transaction"
> standpoint then it's only fair to realize that with payment channel
> tech, orders of magnitude more transactions can be occurring that are
> not measurable on the blockchain. I expect that as payment channel
> tech proliferates, the "per transaction" energy usage will drop
> significantly... but we won't be able to calculate it.

OK, we can revise the energy use estimates once that technology is
deployed.  We will certainly be able to estimate the transaction volume
regardless of what technology is in use.

> In short, this skewed "per transaction energy use" perspective is
> used in order to make Bitcoin sound incredibly wasteful.

Bitcoin is incredibly wasteful: the energy needed to defend the system
exceeds the energy needed to attack it.  We can do much better by just
accepting the existence of banks and designing systems that prevent the
banks from abusing their power.

> You can massage the numbers to make it seem wasteful or not, but the
> reality is that the Bitcoin ecosystem has decided that it is willing
> to pay this cost in order to secure itself against computational
> attack.

There is no "massaging" involved here: Bitcoin consumes vast amounts of
power while processing miniscule numbers of transactions (compared to
other systems).  As I said, we can revisit that issue when "payment
channels" are more widely used, but for the time being, yes, Bitcoin is
a huge waste of energy.

-- Ben

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