Bitcoin Forum

I am by far no expert on the inner workings of Bitcoin but I have wondered about ways in which an outside entity (The Federal Reserve) may try to take down Bitcoin.

I do know that all transactions are stored in the chain. And also that you can get as many addresses as you want. I see these as potential weaknesses against an attack.

For the first one, I may be off but when you download the Bitcoin app you are also downloading all transactions that have taken place right? (I may be way off there). But if someone wanted to attack, they would just create millions of dummy transactions back and forth between two addresses so that the size of the download would get so huge that nobody would be able to load up the client because of the hard drive space needed. Again, I may be way off on how that works but it seems that hard drive space could potentially be an issue if someone went about it right.

As for the BTC addresses, yes I know that there are billions (trillions?) of addresses, but could someone not set up thousands of bots to just keep creating addresses at a speed where they own all BTC addresses after a few years? What is preventing this from happening?

Those are my major concerns. I know that there are major forces out there that do not want Bitcoin or anything like it to succeed, and we are probably off the radar for now as a "currency for trading drugs" but if/when Bitcoin becomes a competitor, we will be attacked.

You forget transaction fees. If they want to do they will be forced to spend thousands of BTC on fees. Let's hope they do that, we will become rich

The fact that you seems to ignore how MANY possible addresses there are.

Thousands of bots? Useless.

Maybe if every planet on every galaxy in the whole universe is covered of bots, then maybe in more than the whole age of the universe they can find how many, 1% of all total addresses?
Mhh.... add some universes.

How do dummy ( ie invalid ) transactions get into the chain? If they are invalid shouldn't they be discarded and never reach the chain?

There are actually ~2 quindicillion possible addresses, it's a number much much higher than trillions.

And it is possible to flood the network with fee-less transactions, but who knows if they will get confirmed, ever.
Not to mention, that it requires bitcoins in the first place.

How would these transactions get in the block chain exactly?

Creating a bitcoin address has no effect on anyone else whatsoever. Creating an address is purely something you do locally. So if they did this, nobody would ever even know.

Now, in order to take your Bitcoins, they'd have to find a private key whose corresponding public key has the same 160-bit hash as your key. The size of the hash was specifically chosen to be way too large to make this possible. The consensus right now is that a 104-bit hash would be safe from such an attack, even against an attack funded by all the resources the human race could muster, until around 2050. A 160-bit hash is 72,000,000,000,000,000 times harder.

I see...so they could flood the network with fee-less transactions back and forth between their own addresses but it would take so long because of lack of fees that it would not be possible to flood it to the point of harm.

That is good to know, I am sure that as regular transactions take up hard drive space over time the hard drives will grow at a fast enough rate where it will not have much affect.

They would have more success ordering the army to gather all the grains of sand from earth than having all the BTC addresses

There have already been several "transaction spam" attacks; as already pointed out, transaction fees keep them from being a big problem.

The code also limits the number of free transactions that are relayed across the network, so you can't flood the network with transactions that will never get mined.

Smarter denial-of-service attack prevention code has been a major unseen feature of the last couple Bitcoin releases.

i distinctly remember the .01 btc attack of last summer that went on for hours/days.  the network handled it well. 

keep up the great work Gavin.