Bitcoin explained
lucaa.org
lucaa.org
> If, say, there’s 50 computers in the network and you’re only connected to 5 who happen to be attackers, they could tell you that you only have 5 coins instead of 20.
No node ever "tells" any information to another. They only pass blocks, blocks either are valid or invalid. If they are valid and part of the main chain, they are the truth. No node ever communicates the balance of a wallet directly, that's the local nodes responsibility.
There is no trust in Bitcoin, that's the entire point.
Yes it does. Nodes "broadcast" information to other nodes. And by information I mean blocks of course. Wanted to keep it as jargon-free as possible.
> There is no trust in Bitcoin, that's the entire point.
This is unfortunately incorrect. You, as a Bitcoin user, require 50% or more trust that the honest nodes in the network can generate blocks at a faster pace than the attackers.
If for whatever reason an attacker generates blocks at a faster pace than the entire network, they could attack you by invalidating your latest payments (simply not accepting them in the block).
To decide if it's possible to cheat bitcoin you have to ask the question: How much money can I steal from people, how much money does it cost for me to steal from people. (and ofcourse how do I turn my stolen bitcoins in something valuable in a short amount of time).
When the value of bitcoin is relatively stable as it is now, that's not likely, but when the value spikes (and outruns hardware investment cost) then perhaps there's a way to cheat.
This blog post is pretty bad, and I suspect the author doesn't actually understand how bitcoin works. The part where the author says "the other 45 in the network know your real amount" implies some sort of voting mechanism, which is not how bitcoin works. This Youtube video is a much better explanation of the technical aspects of bitcoin: http://www.youtube.com/watch?v=Lx9zgZCMqXE
> "the other 45 in the network know your real amount" implies some sort of voting mechanism, which is not how bitcoin works.
Sorry I wasn't implying a voting mechanism. Simply that your account information is controlled by whomever has the majority of the computing power in the network.
Even if the attacker controlled 10% of the computing power of the network, they would only be able to generate approximately one block every hour and a half or so. After a few blocks that would start to look suspicious, since the average time between blocks is supposed to be 10 minutes.
Bitcoin solves this by making the p2p connections as diverse as possible.
http://www.imponderablethings.com/2013/07/how-bitcoin-works-...