Norwegian's forgotten US$25 bitcoins enough to buy luxury flat
Norwegian's US$25 virtual currency purchase in 2009 becomes US$847,000 windfall; he cashes in part of it for an apartment in Oslo

The meteoric rise in the bitcoin virtual currency has meant that within the space of four years, one Norwegian man's forgotten US$25 investment has turned into an US$847,000 windfall.
Kristoffer Koch invested 150 kroner (US$25) in 5,000 bitcoins in 2009, after discovering them during the course of writing a thesis on encryption.
He promptly forgot about them until widespread media coverage of the anonymous, decentralised, peer-to-peer digital currency in April this year jogged his memory.
Bitcoins are stored in encrypted wallets secured with a private key, something Koch had forgotten. It took a full day, but eventually Koch worked out what the password was.
It was then that he got a pleasant surprise.
"It said I had 5,000 bitcoins in there. Measuring that in today's rates it's about NOK5 million (US$847,000)," Koch said.