Greg, thanks! Yes, did find that recently and reference it in the paper. In fact I consider CoinShift an N-way extension of the same techniques.

My guess is that CoinSwap inspired the work on atomic cross-chain transactions (on which I based CoinShift)?

With CoinShift, I'm aiming for shifting ownership of bitcoins (atomic, trustless, decentralized) one step along the cycle found in BCM. (For 1<= i < N, player i transfers to player i+1. Player N transfers to player 1.)

I'll read the CoinSwap post again and explore how it lays out for N players.