DOI:10.1145/2896386 - secure multiparty computations on bitcoin – here’s an interesting scheme using nonstandard bitcoin transactions to insure that honest participants aren’t screwed when executing transactions in the absence of a trusted 3rd party. it has practical gambling and contract enforcement applications.
DOI:10.1145/2896384 - a fistful of bitcoins: characterizing payments among men with no names - yeah, just how anonymous is bitcoin?