Edward V. Murphy, M. Maureen Murphy & Michael V. Seitzinger, Bitcoin: Questions, Answers, and Analysis of Legal Issues (CRS Report R43339) (Oct. 13, 2015) (full-text).
This report has three major sections. The first section answers some basic questions about Bitcoin and the operation of the Bitcoin network and its interaction with the current dollar-based monetary system. The second section summarizes likely reasons for and against widespread Bitcoin adoption. The third section discusses legal and regulatory matters that have been raised by Bitcoin and other digital currencies.