Europe should update its laws to reflect the rise of digital currencies, the head of a bitcoin start-up said, after a successful U.S. auction of bitcoins was seen as a sign of their broadening appeal. "One of the challenges is that without clear guidance from the EU, from the UK, it will limit industry development," said Jeremy Allaire, head of Circle, a bitcoin consumer finance company that allows people to use and store bitcoins online. Read the article: Reuters