I've begun the process of moving a sub-blog into the main blog as a sub archive. I've imported the posts already, and will now need to go through and check that all is well in terms of images etc (I can almost guarantee it won't be). Once I've fixed whatever needs fixing, I shall be redirecting the RSS feeds for the sub-blog to the CATEGORY feed of the new section. This should be seamless for folks reading cryptography - though they may get a one-off glitch of old posts appearing as new when it changes over.
People reading the main blog might get a few extra posts on cryptography (you can always sub to category feeds if you don't like this!) There won't be many though, as I've been all cryptography'd out for a while.
Update: Everything looks good, too good. It turns out that my bad habit of absolute links has saved me. No biggie at the moment, but at some point I really must put that to rights. The feeds have been redirected, and if you're reading this via an old crypto feed then all is well. You will continue to see crypto stuff only (but a full feed, which includes crypto stuff) is available. The reason for this change was that most of my posts have been non-crypto of late and the crypto part was 'out of sight, out of mind'.... now it is back 'in sight'.