4) Growing popularity - Despite the clampdown in some parts of the world, analysts say there's no turning the clock back on digital currencies. A university in Cyprus, a sustainable grocer, a travel website, a delicatessen and a guitar repair shop are just some of the businesses that have received attention online with their decisions to accept bitcoins as payment. Billionaire entrepreneur Richard Branson told CNBC in November that his commercial space flight venture will accept bitcoin as payment. He described bitcoin as "a new exciting currency." Web-based searches for the term 'bitcoin,' which was added to Oxford Dictionaries Online this year, meanwhile have seen a sharp increase since September according to Google data.
"I am fine with the risks, I mean sure it would be nice that it goes to legal status smoothly but regardless, I think the movement would survive and thrive on its own," Sunny King, architect of peercoin, told CNBC earlier this month.
(Read more: Bitcoin – the world's best boost to a brand?)
5) Credible investment? - The Winklevoss brothers think so. Cameron and Tyler Winklevoss, well known for battling Mark Zuckerberg over the origins of Facebook, are big investors in bitcoin and want to create a bitcoin Exchange Traded Fund (ETF) that is accessible to all investors. Also, JP Morgan, the world's largest investment bank, has taken a step towards creating a bitcoin-style currency of its own, filing a lengthy patent for an electronic currency.
"Investors are starting to opt for alternative investments such as bitcoin amid concerns that traditional investments such as the housing market are becoming increasingly risky," Kyle Drake, founder of CoinPunk, an open source hybrid web wallet, said on the sidelines of a bitcoin conference in Singapore in November.
— By CNBC.Com's Dhara Ranasinghe; Follow her on Twitter @DharaCNBC