David G.W. Birch is a director of Consult Hyperion, an IT management consultancy that specializes in electronic transactions. Described by The Telegraph as 'one of the world's leading experts on digital money', by The Independent as a 'grade-A geek', by the Centre for the Study of Financial Innovation as 'one of the most user-friendly of the UK's uber-techies' and by Financial World as 'mad', Dave is a member of the editorial board of the E-Finance & Payments Law and Policy Journal, a columnist for SPEED and well known for his blogs on digital money and digital identity. He is a media commentator on electronic business issues (having appeared on BBC television and radio, Sky and other channels around the world) and has been named by WIRED magazine as one of their global top 15 favourite sources of business and finance information.

This book argues that identity and money are both changing profoundly. Because of technological change the two trends are converging so that all that we need for transacting will be our identities captured in the unique record of our online social contacts. Social networks and mobile phones are the key technologies. They will enable the building of an identity infrastructure that can enhance both privacy and security - there is no trade-off. The long-term consequences of these changes are impossible to predict, partly because how they take shape will depend on how companies take advantage of business opportunities to deliver transaction services. But one prediction made here is that cash will soon be redundant - and a good thing too. In its place we will see a proliferation of new digital currencies.