Bitcoin Forum

In validating a UTXO parser I started looking at various outputs which are provably unspendable.  As of block #305303 2,745.22283996 BTC have been provably lost.  The total number of coins lost is higher potentially much higher but most of those losses can't be proven.   Funds sent to outputs that can never be redeemed can be provably shown to be lost.


* Zero value unprunable outputs are not invalid outputs but they are undesirable.  I was surprised to see there are over three thousand in the UTXO.  In the future the creation of new zero value outputs (with the exception of the prunable OP_RETURN) could be made invalid and potentially even these outputs pruned off by a hard fork.

** As of block 305,303 the coin supply is limited to 12,882,575 BTC.   This is based on the max subsidy per block and the block height.  However the UTXO (set of all unspent outputs) is only 12,882,439.79102854 BTC.  Some of the difference may be due to OP_RETURN outputs (which are unspendable by protocol) having a value set.  This could be accidental or intentional.  Another source of lost coins is due to miners taking less than the maximum block reward which in effect "de-mines" an amount of coins equal to the difference between the allowed reward and the taken reward.

How is this happening ? Is not the reward scheme in the protocol ? Does a miner have choice for his reward ?

I'd like to know whether or not the bitcoins sent to nonexistent public keys should be left lost forever or somehow put back into the ecosystem via increasing the block reward a little bit until they have all been restored (and preventing future coin destruction).

Provably purging coins from the economy may have its advantages, though. Satoshi could send his coins to nowhere, and if bitcoin is ever illegal and the government possesses any of it they can do what they do with ivory: make it stop existing from their vaults.

This is still a pretty dangerous part of bitcoin, because all of these losses have been from faulty coding on the sender's behalf. This loss could have been prevented.

No.

just because coins are unredeemed does not mean they don't belong to anyone and no one has the right to take those coins.

anyone who mined btc with such care can import those keys anytime they like (unless they died in an accident )

Please find one of the thousands of threads discussing the topic you brought up (modifying the protocol).  This thread is only for discussing those coins that are provably lost.

I don't advocate reclaiming outputs but to be clear the ones I identified are invalid.  They will never be spent by anyone no matter how much time passes.  They are zombie coins, they remain unspent but also can never be spent and thus can never be pruned from the blockchain.

Back on topic.  D&T are you asking us to supply other known amounts?  If so you should add the 1.8252962 at https://blockchain.info/address/1BitcoinEaterAddressDontSendf59kuE

A general purpose quantum computer might someday find a private key whose public key corresponds to that address.

No, it won't.

Do we know for certain that Bitcoin's address hash function will never be susceptible to GPQC?

Yes, this has been discussed many, many times.

QC will not help you go from Bitcoin address to public key at all.

If you had the public key then it might help you go from public key to private key, maybe.

Can you point me to some resources about this? Still a bit of a newbie in this regard. :D What makes an output provably invalid?

Grover's algorithm helps some, but currently isn't enough.

Currently-unknown weaknesses in SHA and/or RIPEMD might close the gap someday.

On the other hand, invalid scripts will always be invalid.

OK, fine.

Also, all of the 0.00000001 BTC outputs from this address: 

https://blockchain.info/address/1EtchrGAQGeVbqDRssTTLeYJxWSeYAyaiw

fall into the BurtW says never, jutusranvier says maybe with QC category.

I say "probably never."

Who cares? "Lost" wealth in BTC is the same as wealth donated to every other holder of BTC in the exact proportion of their holdings. It's a self-resolving non-issue.

I care.

Apart from having a funny name, what makes this address so special? It is a valid address isn't it?

So theoretically it could someday be mined, even if it is after several generations?

Mined? What? Do you mean cracked?  Bitcoin mining has nothing to do with keypairs or Bitcoin addresses.

It is a valid Bitcoin address in that it has a valid checksum and it uses valid characters, that is it.  None of the keypairs that map to this Bitcoin address were ever generated or known and, I argue, will ever be known.

Yes.

The protocol allows the miner to claim any reward equal to or less than the sum of the block subsidy and all the transaction fees of all the transactions included in the block.

I'm aware of two coinbases that have identical hash to two others.  This represents a permanent destruction of 100 BTC.

https://blockchain.info/tx/e3bf3d07d4b0375638d5f1db5255fe07ba2c4cb067cd81b84ee974b6585fb468
https://blockchain.info/tx/d5d27987d2a3dfc724e359870c6644b40e497bdc0589a033220fe15429d88599

This is why version 2 blocks embedding block height were created.

What I'm curious about, and it's hard to check without software, is if either of the earlier in time of each of the two was spent before the later one was created.  In which case the coins wouldn't be lost.  I suspect they were unspent and lost, but it'd be cool if someone confirmed.

I think this should be 12,882,550 BTC (or 12,882,600 BTC if including the genesis block reward).

To prove that these bitcoins are invalid one would have to prove that there is no corresponding private key and I suspect that this is a hard problem.