<oembed><type>rich</type><version>1.0</version><author_name>npub1fvuxqdqg7klqqgy3yy8gdxjv4phu92sll5y8zqm2qe5qdrhxymhqf3vq7f</author_name><author_url>https://nostr.ae/npub1fvuxqdqg7klqqgy3yy8gdxjv4phu92sll5y8zqm2qe5qdrhxymhqf3vq7f</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2017-09-22&#xA;📝 Original message:If the variable size increase is only a few bytes, then three possibilities&#xA;arise:&#xA;&#xA;- one should allow signatures to be zero padded (to reach the maximum size)&#xA;and abandon strict DER encoding&#xA;&#xA;- one should allow spare witness stack elements (to pad the size to match&#xA;the maximum size) and remove the cleanstack rule. But this is tricky&#xA;because empty stack elements must be counted as 1 byte.&#xA;&#xA;- signers must loop the generation of signatures until the signature&#xA;generated is of its maximum size.&#xA;&#xA;&#xA;&#xA;&#xA;On Fri, Sep 22, 2017 at 6:39 PM, Mark Friedenbach &lt;mark at friedenbach.org&gt;&#xA;wrote:&#xA;&#xA;&gt; You generally know the witness size to within a few bytes right before&#xA;&gt; signing. Why would you not? You know the size of ECDSA signatures. You can&#xA;&gt; be told the size of a hash preimage by the other party. It takes some&#xA;&gt; contriving to come up with a scheme where one party has variable-length&#xA;&gt; signatures of their chosing&#xA;&gt;&#xA;&gt; &gt; On Sep 22, 2017, at 2:32 PM, Sergio Demian Lerner &lt;&#xA;&gt; sergio.d.lerner at gmail.com&gt; wrote:&#xA;&gt; &gt;&#xA;&gt; &gt; But generally before one signs a transaction one does not know the&#xA;&gt; signature size (which may be variable). One can only estimate the maximum&#xA;&gt; size.&#xA;&gt;&#xA;&gt;&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20170922/2f36b74f/attachment-0001.html&gt;</html></oembed>