<oembed><type>rich</type><version>1.0</version><author_name>npub1nxlvf9mj3jzgue25n5d9y47s3h5hvg0ded9hwpejdxj9mtrs34vs97wjrv</author_name><author_url>https://nostr.ae/npub1nxlvf9mj3jzgue25n5d9y47s3h5hvg0ded9hwpejdxj9mtrs34vs97wjrv</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2014-07-04&#xA;📝 Original message:On Friday 04 July 2014 06:53:47 Alan Reiner wrote:&#xA;&#xA;&gt; ROMix works by taking N sequential hashes and storing the results into a&#xA;&gt; single N*32 byte lookup table.   So if N is 1,000,000, you are going to&#xA;&gt; compute 1,000,000 and store the results into 32,000,000 sequential bytes&#xA;&gt; of RAM.  Then you are going to do 1,000,000 lookup operations on that&#xA;&gt; table, using the hash of the previous lookup result, to determine the&#xA;&gt; location of next lookup (within that 32,000,000 bytes).  Assuming a&#xA;&gt; strong hash function, this means its impossible to know in advance what&#xA;&gt; needs to be available in RAM to lookup, and it&#39;s easiest if you simply&#xA;&gt; hold all 32,000,000 bytes in RAM.&#xA;&#xA;My idea wasn&#39;t to make hashing memory hungry; it was to make it IO-hungry.  It &#xA;wouldn&#39;t be too hard to make an ASIC with 32MB of RAM.  Especially if it &#xA;gained you a 1000x advantage over the other miners.  It seems that sort of &#xA;solution is exactly the one that Mike Hearn was warning against in his blog.&#xA;&#xA;&gt; you&#39;ll only be using a small fraction of it for each &#34;hash&#34;.  This might&#xA;&gt; achieve what you&#39;re describing without actually requiring the full 20 GB&#xA;&gt; of reading on ever hash.&#xA;&#xA;But we want that read.  Remember the actual hash rate isn&#39;t important, what &#xA;matters is how hard it is to reproduce.  If we make it 1000x harder to do one &#xA;hash for everybody, we&#39;re still just as secure.  The difficulty adjustment &#xA;algorithm ensures blocks come at 10 minutes, regardless of hash rate.  So we &#xA;can make it harder by picking a harder algorithm -- SCRYPT or BLOWFISH, or &#xA;just by upping the size of the data that needs hashing.  The advantage of &#xA;upping the size of the input is that, unlike an algorithm change, you can&#39;t &#xA;build a better ASIC to reduce the size.&#xA;&#xA;&#xA;Andy&#xA;&#xA;-- &#xA;Dr Andy Parkins&#xA;andyparkins at gmail.com</html></oembed>