Digital money offers a quick, cheap and convenient medium for money transfers, but its anonymity has raised security fears

Money transfers from family and friends living abroad offer a vital lifeline for people in poor countries. Sending them in digital form is not only swift and easy, but also avoids transaction charges. There is a downside, however: the anonymity of virtual currency leaves it open to abuse by criminals looking to cover their tracks.

Talking to technology experts in Kenya and South Africa about the rise of bitcoin, Mark Anderson hears how the online payment system is helping citizens embrace e-commerce without the need for banks or a centralised structure.

Joining the conversation are technology journalist Toby Shapshak, who discusses how the mobile phone-based money transfer service M-Pesa is now so important to the Kenyan economy that it can create a rise or fall in inflation, and Elizabeth Rossiello from BitPesa, a web-based platform that hopes to emulate M-Pesa's success.

We also hear about the potential dangers of virtual currencies from Eliud Mungai, a Nairobi-based financial services professional, Terlumun Tyendezwa, the head of Nigeria's computer crime prosecution unit, and Terence Chua, Singapore's deputy public prosecutor.