# Re: Where is the separate discussion devoted to possible Bitcoin weaknesses.

Post by: satoshi on August 11, 2010, 10:40:25 PM

It doesn't have to be such a breaking change.  New nodes could accept old transactions for a long time until most nodes have already upgraded before starting to refuse transactions without PoW.  Or, they could always accept old transactions, but only a limited number per time period.

I've thought about PoW on transactions many times, but usually I end up thinking a 0.01 transaction fee is essentially similar and better.  0.01 is basically a proof of work, but not wasted.  But if the problem is validating loads of transactions, then PoW could be checked faster.

A more general umbrella partial solution would be to implement the idea where an unlikely dropoff in blocks received is detected.  Then an attacker would still need a substantial portion of the network's power to benefit from a DoS attack.

Quote from: gavinandresen on August 11, 2010, 04:10:56 PM

> Bitcoin's p2p network is subject to various kinds of denial of service attacks.
>
> There, I said it.

+1

Any demonstration tests at this point would only show what we already know, and divert dev time from strengthening the system to operational fire fighting.

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