Bitcoin in a northern climate: Interesting addresses on ...

Double-spending unconfirmed transactions is a lot easier than most people realise

Example: tx1 double-spent by tx2
How did I do that? Simple: I took advantage of the fact that not all miners have the exact same mempool policies. In the case of the above two transactions due to the fee drop introduced by 0.9 only a minority of miners actually will accept tx1, which pays 0.1mBTC/KB, even though the network and most wallet software will accept it. (e.g. Android wallet) Equally I could have taken advantage of the fact that some of the hashing power blocks payments to Satoshidice, the "correct horse battery staple" address, OP_RETURN, bare multisig addresses etc.
Fact is, unconfirmed transactions aren't safe. BitUndo has gotten a lot of press lately, but they're just the latest in a long line of ways to double-spend unconfirmed transactions; Bitcoin would be much better off if we stopped trying to make them safe, and focused on implementing technologies with real security like escrow, micropayment channels, off-chain transactions, replace-by-fee scorched earth, etc.
Try it out for yourself:
EDIT: Managed to double-spend with a tx fee valid under the pre v0.9 rules: tx1 double-spent by tx2. The double-spent tx has a few addresseses that are commonly blocked by miners, so it may have been rejected by the miner initially, or they may be using even higher fee rules. Or of course, they've adopted replace-by-fee.
submitted by petertodd to Bitcoin [link] [comments]

World Dangerous Dump Truck Operator Skill - Biggest Heavy ... PVC Pipe Bending - YouTube Dynamo's 7 Greatest Magic Tricks Finally Revealed ... STOP Wasting your FireWood ASH! LEARN what we use it for ... bunch of idiots at work!!!! - YouTube

The Bitcoin network was subject to a strange attack this week. Up to 25% of the recorded transactions were modified using a technique called transaction malleability.By examining the Bitcoin blockchain, I've created an hour-by-hour look at the attack. Ein bekannter privater Schlüssel ist der sha256-Hash voncorrect horse battery staplees ergibt:uncompressed address 1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T compressed ... Over a year ago, I contacted the dev myself to at least ask him to at change the default phrase to "do not use this passphrase". Anyone unfamiliar with XKCD comics might reasonably assume that the website's default passphrase, "correct horse battery staple", is in fact a one-time diceware style randomly generated passphrase.. EDIT: As a test, I just sent $.25 to the brain wallet for NEVER USE ... correct horse battery staple: 2012-02-22 13:22:56 UTC: Airwaves: 2011-12-16 00:13:49 UTC: Satoshi Nakamoto: 2011-12-03 04:05:34 UTC: testing 123: 2011-10-13 23:19:19 UTC: one two three four five six seven: 2011-09-14 09:52:04 UTC: Here is another 0.08 BTC waiting to be claimed. 2011-07-15 05:19:40 UTC: This string contains 0.25 BTC hiding in ... Wie dies funktioniert, wählen Sie einen Satz, wie "Correct Horse Battery Staple", und dieser Ausdruck wird konsequent berechnen, um ein Schlüsselpaar zu erstellen, die Sie verwenden können, zu speichern und später wieder abrufen bitcoins. SEIEN Sie EXTREM VORSICHTIG, oder vielleicht tun Sie das nicht bei allen. Es gibt unzählige Roboter ...

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World Dangerous Dump Truck Operator Skill - Biggest Heavy ...

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. This video shows how to bend PVC pipe using boiling water and a jig to hold the desired shape in the pipe. This process was used to construct five rounded ro... inexperience dump truck driver. #homestead #firewood We end up with barrels and barrels of wood ash during the burning season, but there are so many things you can use the ASH for. In today... NBA "He's Not Human" MOMENTS highlights some of the craziest plays in NBA History. It includes displays of insane athleticism and difficult shots from player...