I'm struggling to remember the novel, but there was another book where some aliens created an antimatter-generating system around a star, using the dip in the star's brightness to tell if another civilization was tapping it.

One of their N-removed feudal client races would then come and conquer your primitive society, unless you managed to decode the rest of their message and further demonstrate you were advanced enough to operate your own government across relativistic distances and timespans.

The premise sounds like Count To A Trillion by John C. Wright.

Of which I loved the idea, but was very disappointed by the realization.

That's it, thanks.

Krugman and Stross seem to be fellow travelers.

1. Neptune's Brood is more heavily based on David Graeber's work on Debt (notably Debt: The First 5000 years).

1a. If you feel inclined to read Neptune's Brood, I've got one big regret: I wrote it circa 2010-11, before BitCoin really took off in the public eye, and used the term "bitcoin" for a not-like-our-BtC-honest cryptocurrency. (If I'd known BtC was going to take off that way the year the book came out, I'd have come up with a different name.)

2. Paul Krugman is a cool person to go drinking with in a pub :)

Hi Charlie,

I enjoyed the book a lot, and I was only a bit irked by the slightly-off Bitcoin references and the countersigning etc.

I have a few pages written on the same idea of many disparate colonies but with the twist that quantum entanglement allows for limited FTL communications, which makes an interstellar blockchain feasible.

I'm looking forward to your next book.

The next book ("The Rhesus Chart") came out last July; there are five books in various stages of production after that ... and none of them deal with cryptocurrency or space colonization or the singularity: this decade I'm doing urban fantasy (plus my big fat post-Edward Snowden security state near-future technothriller).