Thank You to everyone that honoured the bounty. All payments have been received.
Next on my TODO list is to make an API call that merchants can use.
Topic: [BOUNTY] Bitcoin blockchain monitoring site (Read 8423 times)
Sent and thanks
Just sent my 5 BTC.
New Address 1JArS6jzE3AJ9sZ3aFij1BmTcpFGgN86hA
paid my 10 BTC pledge
Received, cheers Tycho.
New Address 1JArS6jzE3AJ9sZ3aFij1BmTcpFGgN86hA
My pledge is paid (50 BTC). Would be nice if you can add info about which blocks they belong and which one is orphaned.
Added.
You are correct, I haven't been active but I am a man of my word. Where shall I send my 5 BTC?
Thats great, Thank you to the both of you.
New Address 1JArS6jzE3AJ9sZ3aFij1BmTcpFGgN86hA
I PM'd the other bounty contributors, but I don't think they are active anymore.
Post a fresh address here, so award can be sent and checked by people. I PM'd the other bounty contributors, but I don't think they are active anymore.
You are correct, I haven't been active but I am a man of my word. Where shall I send my 5 BTC?
Would be nice if you can add info about which blocks they belong and which one is orphaned.
Probably just accidental:
http://blockchain.info/tx-index/14760752/2c412e1ab2c66590f9be8d43e4d787eeaca167cec9a6a5f57651482ef2e737aa?show_adv=true
http://blockchain.info/tx-index/14760749/5a875fe607947f5d914eb5ef2ba7c7f6fb2319ceb77485297a7df520ccf7def0?show_adv=true
Two very similar, but with one different output address. The value probably isn't high enough to be malicious.
http://blockchain.info/tx-index/13084119/c407cc2973c191e50f6ef01630b417d0814e5030f493629c062a5852e94b8bd0
Is the only double spend between different orphaned branches in the entire database. I imported the blockchain from bitcoinchart's dump which contains orphaned blocks from way back in 2010, so it looks like there hasn't been any successful double spend attempts of any value.
http://blockchain.info/tx-index/14760752/2c412e1ab2c66590f9be8d43e4d787eeaca167cec9a6a5f57651482ef2e737aa?show_adv=true
http://blockchain.info/tx-index/14760749/5a875fe607947f5d914eb5ef2ba7c7f6fb2319ceb77485297a7df520ccf7def0?show_adv=true
Two very similar, but with one different output address. The value probably isn't high enough to be malicious.
http://blockchain.info/tx-index/13084119/c407cc2973c191e50f6ef01630b417d0814e5030f493629c062a5852e94b8bd0
Is the only double spend between different orphaned branches in the entire database. I imported the blockchain from bitcoinchart's dump which contains orphaned blocks from way back in 2010, so it looks like there hasn't been any successful double spend attempts of any value.
Tycho, When I initially made the double spend page there was only one transaction, now there are 6. Is that you testing it?
No, I'm not.I think that it's some broken client or attack against some broken client.
You can try to monitor for transactions with multiple instances of same input, that's what happens too, as my monitoring nodes show.
I heard that there was some old client storing them in memorypool or doing something else.
UPD: Also it may be caused by people restoring their wallets from backups or using wallet.dat copy accidentally.
What we should especially care for is double-spend attempts in orphaned branches.
Tycho, When I initially made the double spend page there was only one transaction, now there are 4. Is that you testing it?
I PM'd the other bounty contributors, but I don't think they are active anymore.
I PM'd the other bounty contributors, but I don't think they are active anymore.
Hello.
Do any of pledgers have any other opinion about if this solution meets requirements and should be awarded ? Looks like it does.
Do any of pledgers have any other opinion about if this solution meets requirements and should be awarded ? Looks like it does.
I know this bounty is old, but I think blockchain.info meets the requirements to claim it.
Orphaned Block tracking:
http://blockchain.info/orphaned-blocks
Live list of unconfirmed transaction, if any double spends are detected they will be marked.
http://blockchain.info/unconfirmed-transactions (available in JSON with ?format=json)
Double spend list:
http://blockchain.info/double-spends
Thanks
Orphaned Block tracking:
http://blockchain.info/orphaned-blocks
Live list of unconfirmed transaction, if any double spends are detected they will be marked.
http://blockchain.info/unconfirmed-transactions (available in JSON with ?format=json)
Double spend list:
http://blockchain.info/double-spends
Thanks
I think, this could be also useful also estimating - how blocks to wait for considering transaction fixed in block chain.
Ex. if statistics shows, that one block is orphaned with 1% probability, 2 blocks with 0.01%, 3 blocks with 0.0001%, so it does not require to wait 4th block if you are not afraid of <0.0001% probability.
Ex. if statistics shows, that one block is orphaned with 1% probability, 2 blocks with 0.01%, 3 blocks with 0.0001%, so it does not require to wait 4th block if you are not afraid of <0.0001% probability.
No, it won't. Currently orphaned blocks are accidental due to (almost) simultaneous finding a new block by two miners. Waiting for confirmations is to make sure there are no intentional chain splits. Intentional chain splits are possible with small probability even for an attacker that have <50% of hashspeed. And you won't know it until it's tried. If you have 10% of hashspeed, you will get two blocks in a row with 1% probability. So you can reverse 1-confirmation transactions once in 100 blocks if you try. Current orphanage rate shown that nobody tried it yet but does not tell you how probable is that someone will try it.
1) Real time list of blocks, including orphaned ones
I think, this could be also useful also estimating - how blocks to wait for considering transaction fixed in block chain.Ex. if statistics shows, that one block is orphaned with 1% probability, 2 blocks with 0.01%, 3 blocks with 0.0001%, so it does not require to wait 4th block if you are not afraid of <0.0001% probability.
If he's asking for a program that to show all orphaned blocks on the network, will a program be able to see all orphaned block behavior on the network or only the behavior of the local node that it's pulling data from?
Only local. But any "evil forks" has to be distributed in order to make sense. Any node that has a "good" chain will detect injection of longer "evil" chain because it will trigger reorganization. The only thing that cannot be easily detected are dying forks. A fork that is growing independently but is outrun by the main chain because such fork may never reach your node.
Quote
It sounds like a supernode could accomplish this without too much trouble since it has multiple connections to have the most up to date block chain info and can listen to all transactions like bitcoinmonitor does. Someone would just have to develop the code to identify the forks?
It is possible. I remember theymos (owner of blockexplorer) stated he had plans to incorporate blocks forks. The only problem is that because it is so rare, it is quite difficult to debug the code. You can create forks on testnet but it is also quite troublesome.
This type of forks is easy to detect. Every time it happens, bitcoin deamon prints "REORGANIZE" is debug.log. There is one every a few thousand blocks due to coincidental finding two blocks at roughly the same time. After that miners try to add to the chain they received first. If the one that won the race is not the one you have stored as the longest in memory, the chain reorganizes. For those who has the other chain, nothing will be printed in debug.log because no reorganization takes place.
If he's asking for a program that to show all orphaned blocks on the network, will a program be able to see all orphaned block behavior on the network or only the behavior of the local node that it's pulling data from?
You need to look if the forked chain contains the transactions that are inconsistent with the previous chain.
Since the client requires 5 confirmations, any shorter than 5 fork cannot reverse any confirmed transactions. So detecting large forks is the very first step in finding potential problems.
I have never seen a fork longer than 1 on mainnet (I have seen some on testnet) and it is very rare by accident. I remember that on IRC someone claimed that after the very first slashdoting in July last year, the blocks were generated so quickly (and the network was smaller), there were quite a few longer than 1 accidental chain splits.
Since the client requires 5 confirmations, any shorter than 5 fork cannot reverse any confirmed transactions. So detecting large forks is the very first step in finding potential problems.
I have never seen a fork longer than 1 on mainnet (I have seen some on testnet) and it is very rare by accident. I remember that on IRC someone claimed that after the very first slashdoting in July last year, the blocks were generated so quickly (and the network was smaller), there were quite a few longer than 1 accidental chain splits.
It sounds like a supernode could accomplish this without too much trouble since it has multiple connections to have the most up to date block chain info and can listen to all transactions like bitcoinmonitor does. Someone would just have to develop the code to identify the forks?
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