Bitcoin Forum

Hi, I couldn't find any mention of this so I thought I'd bring it up. What happens if a person holds on to their coins for a long time, say 10 years? At the time, it may have been hard to forge an alternate history for the coins, but 10 years later, it may be much easier. Would this enable attackers to steal the coins?

If this is true, would it be a good practice to create dummy transactions to yourself (don't know if this is possible) every month or so to safeguard your coins?

The software doesn't work that way. Old transactions are not discarded. 

Also, the ability to spend your bitcoins requires the encryption keys that are in your wallet.
   - http://en.bitcoin.it/wiki/How_bitcoin_works#Cryptography

Your coins are protected by the work done to create all the blocks after them in the block chain.  Since the difficulty has been periodically adjusted to account for increases in computing power, it does not become any easier to steal your coins with the passage of time, and in fact, it becomes far more difficult.

So dummy transactions are not necessary.

Stephen Gornick - good point. I guess this would only work if person A paid coins to person B. Person B held on to them for a long time. Person A then paid the same coins to person C.

Enochian - if subsequent transactions by any person protect my previous transactions, then my whole point was moot. I think that's what you're saying. I wasn't sure from reading http://www.bitcoin.org/bitcoin.pdf. Is there a more detailed document?

Check the wiki (https://en.bitcoin.it/wiki/Main_Page).

Well, I took your comment about "forge an alternate history for the coins" to question whether creating an alternative block chain to the one containing your transaction would become easier with the passage of time due to advances in processing power.  This doesn't happen, as subsequent blocks have increased difficulty factored in, so you're always adding blocks based on the prevailing system wide hash rate.

Bear in mind that the only thing the published block chain does is prevent double spending.  All other attack vectors against Bitcoin, like stealing coins, or spending other peoples coins, are secured by the cryptography using the private keys stored only in your wallet.

If something bad happens to Bitcoin, it will more likely be a bug or the government, and not some inherent weakness in the thinking underlying the protocol.

thanks guys