Yahoo has disclosed that it was victim to a massive data breach in 2013, in a cyber attack that compromised data of more than a billion users. It follows a disclosure from the internet company in September of a separate breach that affected more than 500 million accounts.User names, telephone numbers, passwords and email addresses were stolen, but not bank and payment data. Cynthia Brumfield, a Washington cyber security consultant, tells us what this reveals about security standards at Yahoo.

As Donald Trump reveals more names of the people he wants to join his cabinet we are getting a better picture of the shape of the next administration in the White House. He has selected Rick Perry, former governor of oil rich Texas, to lead the Department of Energy and his choice to nominate Rex Tillerson, the chief executive of ExxonMobil, as Secretary of State is controversial. Mr Trump also wants a former Goldman Sachs banker, Steven Mnuchin, for Treasury Secretary. Our regular US economic commentator, Irwin Stelzer, gives us his thoughts on what these choices signal about how Donald Trump might govern.

Europe's Galileo satellite navigation system went live today, after 17 years of planning with numerous setbacks and going three times over budget. It promises to outperform rivals like America's GPS, but with 18 satellites in place so far, Galileo's signal will need to be boosted by GPS satellites operated by the US. Thierry Dubois, France bureau chief for the magazine and website Aviation Week in Lyon, tells us more about Europe's new satellite navigation system.

Imagine being forced to leave your home, a where you feel comfortable, to uproot your life to another country, thousands of kilometres away. That is the sad fate for millions of the world's refugees and asylum seekers, as record numbers of people this year have had to flee from conflict, in countries like Syria and Afghanistan. However for some refugees in the Indian capital Delhi it is not all bad news, as women from Afghanistan are cooking up a project that is helping them get back on their feet. The BBC's Sumiran Preet Kaur reports.

Health experts constantly remind us that getting enough sleep and exercise are two major factors that help people perform better at work. Perhaps time to consider a new resolution for 2017, but easier said than done. Dr Steven MacGregor is the founder of the Leadership Academy of Barcelona, and as an expert on workplace health he explains how we can improve business performance.

(Picture: Yahoo headquarters in California. Getty Images.)