<oembed><type>rich</type><version>1.0</version><author_name>npub1g6vxlp4e0nyhs2dqxxcryztyf5f5hyuaq93nw4r87zcnv0sdsa0qqsl5wd</author_name><author_url>https://nostr.ae/npub1g6vxlp4e0nyhs2dqxxcryztyf5f5hyuaq93nw4r87zcnv0sdsa0qqsl5wd</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2017-05-23&#xA;📝 Original message:On Mon, May 22, 2017 at 9:00 PM, Paul Sztorc &lt;truthcoin at gmail.com&gt; wrote:&#xA;&#xA;&gt; I would replace &#34;Bitcoins you manage to steal&#34; with &#34;Bitcoins you manage&#xA;&gt; to double-spend&#34;. Then, it still seems the same to me.&#xA;&gt;&#xA;&gt;&#xA;With double spending, you can only get ownership of coins that you owned at&#xA;some point in the past.  Coins that are owned by someone else from coinbase&#xA;to their current owners cannot be stolen by a re-org (though they can be&#xA;moved around).&#xA;&#xA;With BMM, you can take the entire reserve.  Creating a group of double&#xA;spenders can help increase the reward.&#xA;&#xA;&#xA;&gt;&#xA;&gt; It may destroy great value if it shakes confidence in the sidechain&#xA;&gt; infrastructure. Thus, the value of the stolen BTC may decrease, in addition&#xA;&gt; to the lost future tx fee revenues of the attacked chain.&#xA;&gt;&#xA;&gt; http://www.truthcoin.info/blog/drivechain/#drivechains-security&#xA;&gt;&#xA;&gt;&#xA;That is a fair point.  If sidechains are how Bitcoin is scaled, then&#xA;shaking confidence in a side-chain would shake confidence in Bitcoin&#39;s&#xA;future.&#xA;&#xA;I wasn&#39;t thinking of a direct miner 51% attack.  It is enough to assume&#xA;that a majority of the miners go with the highest bidder each time.&#xA;&#xA;If (average fees) * (timeout) is less than the total reserves, then it is&#xA;worth it for a 3rd party to just bid for his theft fork.  Miners don&#39;t have&#xA;to be assumed to be coordinating, they just have to be assumed to take the&#xA;highest bid.&#xA;&#xA;Again, I don&#39;t really think it is that different. One could interchange&#xA;&gt; &#34;recent txns&#34; (those which could be double-spent within 2-3 weeks) with&#xA;&gt; &#34;sidechain deposit tnxs&#34;.&#xA;&gt;&#xA;&#xA;It is not &#34;recent txns&#34;, it is recent txns that you (or your group) have&#xA;the key for.  No coordination is required to steal the entire reserve from&#xA;the sidechain.&#xA;&#xA;Recent txns and money on the sidechain have the property that they are&#xA;riskier than money deep on the main chain.  This is the inherent point&#xA;about sidechains, so maybe not that big a deal.&#xA;&#xA;My concern is that you could have a situation where an attack is possible&#xA;and only need to assume that the miners are indifferent.&#xA;&#xA;If the first attacker who tries it fails (say after creating a fork that is&#xA;90% of the length required, so losing a lot of money), then it would&#xA;discourage others.   If he succeeds, then it weakens sidechains as a&#xA;concept and that creates the incentive for miners to see that he fails.&#xA;&#xA;I wonder how the incentives work out.  If a group had 25% of the money on&#xA;the sidechain, they could try to outbid the attacker.&#xA;&#xA;In fact, since the attacker, by definition, creates an illegal fork, the&#xA;effect is that he reduces the block rate for the side chain (possibly to&#xA;zero, if he wins every auction).  This means that there are more&#xA;transactions per block, if there is space, or more fees per transaction, if&#xA;the blocks are full.&#xA;&#xA;In both cases, this pushes up the total fees per block, so he has to pay&#xA;more per block, weakening his attack.  This is similar to where transaction&#xA;spam on Bitcoin is self-correcting by increasing the fees required to keep&#xA;the spam going.&#xA;&#xA;Is there a description of the actual implementation you decided to go with,&#xA;other than the code?&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20170523/69551868/attachment.html&gt;</html></oembed>