Feature Request: keybase blog posts with selective visibility/encryption

As a keybase user, I would like to post blog entries to a personal top-level blog that would only be visible within the keybase client app.

The posts would be in markdown format, lengthier than tweets or chat messages, but not novel-length. Embedded or linked media/images and attachments could be served from my keybase public shared folder.

The visibility for posts would be either 1/ key-signed, but not encrypted, public blog posts (visible to any keybase user), or 2/ encrypted blog posts (only visible to an ad-hoc list of individuals or teams, specified on a per-post basis).

Furthermore, it might be nice if I could grant retroactive access to a stream of encrypted non-public blog posts tagged with a specific #hashtag. e.g., grant @susan access to all of my #secretbbqrecipe blog posts, past and future.

The killer application is personal blogging, with selective visibility for each blog post or #topic.

Further review is required of cryptographic limitations and challenges for larger ad-hoc lists of individuals and teams, however it seems that with the keybase platform we could be in a position to solve this problem.

The blog feature could potentially be built on top of the keybase public/private file sharing sub-system. Or, the implementation could potentially resemble a # blog chat channel, with special visibility controls (default visibility and ad-hoc per-post visibility controls).

No files, tests, or implementation entry points are named. Start by reviewing the keybase public/private file-sharing subsystem and the proposed blog chat channel model, then assess cryptographic limits for larger ad-hoc lists. Done would require a scoped design for markdown posts, per-post visibility, and hashtag-based retroactive access.