Call it human nature, but ever since the invention of paper money, people have tried to imitate and counterfeit it. The result has been an unending race between issuing authorities and perpetrators. This article, which is based on my contributions to the Banknote 2009 and 2010 Currency conferences, is a review of how authorities have historically tried to deter counterfeiting and how they have responded to new threats. From this perspective, I will then explain the role of the Central Bank Counterfeit Deterrence Group (CBCDG) and its activities, concluding with a short assessment of recent developments in counterfeit production techniques and how to address future threats.
