📅 Original date posted:2015-09-29
📝 Original message:Jonathan Toomim (Toomim Bros) via bitcoin-dev 於 2015-09-29 09:30 寫到:
> SPV clients will appear to behave normally, and
> will continue to show new transactions and get confirmations in a
> timely fashion. However, they will be systematically susceptible to
> attack from double-spends that attempt to spend funds in a way that
> the upgraded nodes will reject. These transactions will appear to get
> 1 confirmation, then regress to zero conf, every single time. These
> attacks can be performed for as long as someone mines with the old
> version.
1. Who told you to accept 1-confirmation tx? Satoshi recommended 6
confirmations in the whitepaper. Take your own risk if you do not follow
his advice.
2. This is true only if your SPV client naively follows the longest
chain without even looking at the block version. This might be good
enough for the 1st generation SPV client, but future generations should
at least have basic fraud detecting mechanism.
> If an attacker thinks he could get more than 25 BTC of
> double-spends per block, he might even choose to mine with the
> obsolete version in order to get predictable orphans and to trick SPV
> clients and fully verifying wallets on the old version.
This point is totally irrelevant. No matter there is a softfork or not,
SPV users are always vulnerable to such double-spending attack if they
blindly follow the longest chain AND accept 1-confirmation. The fiat
currency system might be safer for them.
jl2012 at xbt.hk [ARCHIVE] /
npub1kc…wjfw4
2023-06-07 17:41:37
in reply to nevent1q…y5mh
Author Public Key
npub1kc0zulxt7j4a0ayhzhrz7jk84y7tm4026qcky7w97hlfkxxap24qnwjfw4Published at
2023-06-07 17:41:37Event JSON
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"content": "📅 Original date posted:2015-09-29\n📝 Original message:Jonathan Toomim (Toomim Bros) via bitcoin-dev 於 2015-09-29 09:30 寫到:\n\u003e SPV clients will appear to behave normally, and\n\u003e will continue to show new transactions and get confirmations in a\n\u003e timely fashion. However, they will be systematically susceptible to\n\u003e attack from double-spends that attempt to spend funds in a way that\n\u003e the upgraded nodes will reject. These transactions will appear to get\n\u003e 1 confirmation, then regress to zero conf, every single time. These\n\u003e attacks can be performed for as long as someone mines with the old\n\u003e version.\n\n1. Who told you to accept 1-confirmation tx? Satoshi recommended 6 \nconfirmations in the whitepaper. Take your own risk if you do not follow \nhis advice.\n\n2. This is true only if your SPV client naively follows the longest \nchain without even looking at the block version. This might be good \nenough for the 1st generation SPV client, but future generations should \nat least have basic fraud detecting mechanism.\n\n\n\n\u003e If an attacker thinks he could get more than 25 BTC of\n\u003e double-spends per block, he might even choose to mine with the\n\u003e obsolete version in order to get predictable orphans and to trick SPV\n\u003e clients and fully verifying wallets on the old version.\n\nThis point is totally irrelevant. No matter there is a softfork or not, \nSPV users are always vulnerable to such double-spending attack if they \nblindly follow the longest chain AND accept 1-confirmation. The fiat \ncurrency system might be safer for them.",
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