Mass user authentication Dedicated authentication servers Can afford a ROM-in-RAM large enough to buy ~5 years of anti-botnet 128 GB to 512 GB of RAM is now easily affordable for servers, but is still way beyond what's found in typical botnet nodes Current desktop CPUs are commonly limited to addressing 32 GB of RAM, and actual botnet node RAM sizes are typically even less (of course, this will be changing) The gap between supported RAM sizes of commodity servers and botnet nodes is likely to persist even as actual sizes grow As an option, can use a ROM-on-SSD (terabytes?), which has pros and cons compared to ROM-in-RAM yescrypt supports both kinds, and we ran tests with SSD too