How porn links and Ben Bernanke snuck into Bitcoin's code

Here's a little-known quirk of cyber currency Bitcoin: There are coded messages hidden in the ledger that track bitcoin transactions. Most are innocuous, but this week, the discovery of a malicious transmission filled with porn links set the Bitcoin community abuzz.

Bitcoin, a four-year-old digital currency developed by a hacker who still remains anonymous, is a favorite plaything of libertarians and cryptography geeks. It burst into the mainstream this year when investors took note of its wild price swings. One bitcoin is now worth around $112, down from a record high of $266 last month, but up from $5 a year ago.