Agree with all of these, what I'm not clear on is whether bitcoin needs to be backed by electricity (since it is backed by the other things). I understand that the mining process puts a price on the blockchain and is a security feature, but on the other hand it is wasteful of electricity! So is this there just so that bitcoin will be backed by something real (i.e. electricity and computational power)? Is it necessary? And could other approaches that require less energy (e.g. Litecoin, proof-of-stake) work just as well?