"Ittay Eyal and Emin Gun Sirer, of Cornell University in New York have discovered the "devastating" potential for Bitcoin "mining" – the process by which Bitcoins are generated – to be manipulated (arxiv.org/abs/1311.0243v1)." rapporterar NewScientist.com den 6 nov 2013.

De som inte vet hur Bitcoin fungerar kan läsa White TV:s inslag

White TV avråder från Bitcoin: luktar pyramidspel och

Bitcoin Ponzi Scheme bubble crashade

Nu har dessa vetenskapsmän listat ut följande: "Bitcoins are generated when people connect their computers to the network and set them to work on a cryptographic puzzle. This is known as mining. When a puzzle has been solved it adds a digital "block" to the public record of all Bitcoin transactions, known as the "blockchain". The miners are then rewarded with a set amount of Bitcoins.

The blockchain is occasionally split into branches when separate users generate blocks from the same previous block. Miners agree to work on the longest branch, so as soon as one of these branches becomes longer than the other, the shorter branch is abandoned.

Although groups form to share computing power and split the profits, what they receive is proportional to the resources they contribute.

Selfish mining

However, the research argues that it is theoretically possible for one group to gain an advantage by engaging in what the authors call "selfish mining".

In this scenario, the group does not release solutions to solved cryptopuzzles. Instead, it mines a branch in secret, hiding it from honest miners.

Lengthening the private chain would make it the dominant one when eventually released. The group would then get a higher share of coins than is fair for the resources they have contributed because they have forced other miners to waste computing power on the original chain. The problem gets worse as the selfish group recruits extra members.

Sirer, who describes the problem on his blog , says: "Until now we thought that if the attackers were in a minority they would be ineffective but suddenly we've shown that no, that doesn't have to be the case." ........

"Bitcoin has traditionally been understood as relatively safe to invest in. It is extremely difficult, for example, to counterfeit. However, Eyal and Sirer's findings are now being investigated by members of the Bitcoin community.

"The attack is very clever, and unfortunately it will work," says Bitcoin developer Peter Todd. (bold by White TV) "There's been a tendency for the Bitcoin community to assume miners always have the best interests of Bitcoin in the long term in mind. So far this has generally proven to be true, but as mining becomes less profitable due to the inflation rate dropping (it halves every 4 years) I think we'll see more and more selfish behaviour."

Another Bitcoin developer, Mike Hearn, adds that if the technique worked, it would have a negative impact on Bitcoin as a whole, leaving everyone, including the selfish miners, at a loss, just when the currency was starting to be taken seriously by the international community: "If miners were to start attacking the system or seizing control of it, confidence in Bitcoin would be severely hurt and the value would fall." avslutar NewScientist.com

Denna upptäckt är ytterligare ett argument att inte använda sig av Bitcoin. Vilken garanti har vi egentligen att det inte blir fler än 21 miljoner bitcoins? Vem kontrollerar det?

Denna totala begränsning av bitcoins och deras ständiga försvinnanden genom hårddiskhaverier, som ingen har en överblick över,  måste leda till deflation i betydligt värre utsträckning än guldmyntfoten, då vi alltid kan hitta ny guld i jorden, även om det har blivit svårare och dyrare.

källa

Australiensisk Bitcoinbank Inputs.io rånad på 4 100 bitcoins värda ca. 1,3 M USD

Russia Today rapporterade den 8 nov 2013 att den australiensiska bitcoin banken inputs.io förlorade 4 100 bitcoins i en hacker attack den 26 okt 2013. Kunderna har förlorat allt till ett värde av sammanlagt 1,3 M USD.

"The operator indicated the attack was possible due to “a flaw” in the system which allowed the hackers to bypass the protection." skriver RT.

Det är naturligtvis inte första gången att Bitcoin utsatts för en hacker attack. Så kan det gå när man deltar i något som luktar pyramidspel.