(well still on miranda IM, i'll migrate to ng very soon too) and i never needed password for startup, found no plugin for that
Miranda IM has whole other database driver for that - DbX_mmap_SA - with its own cryptors. Standard Miranda IM driver must be swapped for this one, and only then DB encryption is possible.
Miranda NG has encryption built-in, uses Standard encryption turned on by default, Total encryption and password for entrance are optional, users have no headache now, it all works right "from the box", no plugin exchange or additional plugins required. It is also much faster and more secure than previous encryption type in Miranda IM.