Since my following quesiton is quite similar to this one Why is mining necessary for the Bitcoin network/system? I'm referring to the mentioned points of the accepted answer of this question that does in my opinion not answer the question at all or quite consice even though the answer is very long it just does not refer to the question. I'll explain why I make that statement.

Fairness - No massive energy consuming process is required (mining) ==> Does not answer the why mining

Stability - He also does not answer the why question he just assumes it is neccessary and explains the why a tranaction os not irreversible process in more detail. But he does not answer the why mining is required question, again he just assumes it is required and then explains a process built on that assumption.

Safety and security - At the last paragraph of this he comes up with a reason. The 51% attack. Is this the only reason that mining is required?

I'll also ask the question again: We could just hash the block without a nonce and it is also checksummed and the data integrity is ensured just as well as with a nonce. So why we need the nonce that requires such a massive energy consuming process? Is it only avoid avoid a 51% attack?

  • It seems to me that your questions are answered in these two related topics: Is there a way to set up proof-of-work systems so they would be even more useful?, What exactly is Mining?
    – Murch
    Jun 19, 2017 at 21:04
  • Can you explain exactly what you're proposing? If I have 10 bitcoins and I produce two transactions, one sending them to address A and one sending them to address B, how do you ensure we all agree which one of those two is valid? And without such a mechanism, how can anyone ever be sure they can form a transaction others will accept as valid? PoW was the first solution to the double spend problem that didn't require a central authority. There are now others, but it's a hard problem that won't solve itself by magic. Jun 19, 2017 at 22:37

2 Answers 2


It is at least partially connected to the problem of initial distribution: In the early days when no one had bitcoins, who should get bitcoins?

Initial Distribution

Without proof that someone put in substantial effort mining a block, anyone could mine a block in seconds. Any hash value would work, and anyone could claim the reward. New blocks would be "mined" at the rate of dozens per second, or even more. All of those people would claim bitcoin rewards for mining, without having done any real effort. That would make bitcoin worthless, because anyone could collect as many bitcoins as they wanted as fast as they wanted.

Resolving Forks

Little or no Proof of Work would also make the blockchain horribly forked. With new blocks being mined at an incredible rate, forks in the chain would appear constantly, and some of those forks would fork again, creating a massive tree of branches. A goal of the block-chain is to have one single chain with consensus around it. That goal is furthered by making mining a slow and difficult task. New blocks are discovered relatively rarely, so the consensus of miners gathers around just two forks in the chain, and those forks get resolved back to a single chain relatively quickly.

  • So the only reason is to get coins in the network? If that's the only reason then in myopinion bitcoin is desgined wrong in terms of our environment in that we all live (earth). Why not just randomly reward somebody. At the moment it is also random (kind of if everybody would mine it would be completely random). So I can also get coins in the network by just giving them away randomly. I'm not sure but I guess the forkproblem can be solved by code.
    – Ini
    Jun 19, 2017 at 17:27
  • "I guess the fork problem can be solved by code" Go ahead and try it.... if you could come up with a robust solution, then you'd be a better computer scientist than 99.9% of all programmers on the planet. It is a HARD problem.
    – abelenky
    Jun 19, 2017 at 17:30
  • So the fork problem if the root? That is the why?
    – Ini
    Jun 19, 2017 at 17:31
  • As I think my answer made clear: Hard Mining and PoW solves several different problems at once. Looking for a single one-and-only "why" is pointless. The "why" has multiple facets to it: It solves initial distribution, resolves forks, discourages malicious actors, sets a value basis, etc. Why? because it works; thats why.
    – abelenky
    Jun 19, 2017 at 17:34
  • You mentioned two things (Initial Distribution, Resolving Forks). I think my comment made Initial Distribution kind of obsolete. So we are left with Resolving Forks. If you don't mind you can explain the other facets. It's a really simple question and in gernal to a really simple question that exaclty points to one thing there is only one thing as answer and not multiple things. The other things are nice benefits but not the root. Could be a programming principle, because I think it's always like that :D
    – Ini
    Jun 19, 2017 at 17:38

I'm going to reference your original question, especially the text:

If I send 10 BTC to someone, why does someone else (a "miner") need to verify this? Shouldn't this transaction be stored in a DB somewhere, and verifiable by querying that DB?

The answers to that question were pretty good:

Where would the DB be? If the DB is stored in some centralized location, then Bitcoin is no longer decentralised.

The whole point of BitCoin is that there is no central authority that everyone has to trust for accuracy, reliability, solvency, and incorruptibility.

Anyone who wants can keep their own copy of the "database", which is impossible to manipulate, corrupt, forge, delete, etc.

This particularly manifests itself in the double-spend. From your original question: If I send 10 BTC to someone, why does someone else need to verify this?"

What if you send the same 10 btc to two different people? We need to be sure that only one transaction succeeds, and the other fails. Mining is how double-spends are prevented and only one transaction gets committed.

You'll probably come up with some other nutty scheme for dealing with double-spending, and it will inevitably be flawed. This is an extremely hard problem in computer science, and anything you think will work has already been tried.

  • I don't think that wasting energy or making rich richer is the solution to problems. There must be a more intelligent solution, I don't think that this is the end of the evolution of this topic and everything has already been tried. If you don't question things that's not very good, this should be pretty obvious.
    – Ini
    Jun 19, 2017 at 20:16
  • Good luck with that. You're obviously not here seeking an answer to a question. You are apparently here to argue some obtuse and unclear point. You are rejecting detailed, experienced and rational answers simply because you don't like them.
    – abelenky
    Jun 19, 2017 at 20:18
  • Ehh no my quesiton is pretty simple and I try to get an answer
    – Ini
    Jun 19, 2017 at 20:25
  • You got 9 good answers on your original question and its duplicates, then I gave you two more here. Without ever showing that you understand and appreciate those answers, your best response is "There must be a more intelligent solution". (That is a very poor argument)
    – abelenky
    Jun 19, 2017 at 20:28
  • the thread im refering too is not from me. And the accepted answer there does not refer too the question as already mentioned in the opening post. I think the fork answer from you here is the only reasonable answer so far but I'm not convinced.
    – Ini
    Jun 19, 2017 at 20:41

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