Social networking giant Facebook has opened registration for its third annual Hacker Cup, set to begin from January 25. 

The top prize will be $ 10,000 (approx. Rs 5.5 lakh) as against $ 5,000 (Rs 2.75 lakh) last year and as many 25 of the best hackers will be taken to Facebook's headquarter in USA, a statement said. 

The Facebook Hacker Cup is an annual worldwide programming competition where hackers compete against each other for fame, fortune, glory and a shot at the coveted Hacker Cup. 

"The competition will be held in two rounds starting with an online qualification, out of which 25 of the best hackers are then flown by Facebook to their headquarters inMenlo Park, CA," Facebook said. 

"The preliminary round will be held between January 25 and February 16 while the onsite final round is scheduled for March 22-23, 2013. 

Contestants will be judged on accuracy and speed as they race to solve algorithmic problems to advance through up to five rounds of programming challenges," it added. 

Last year, the Hacker Cup attracted 8,000 participants from 150 countries, with the winner- Roman Andreev, hailing from Russia, Facebook said. 

"Hacking is core to how we build at Facebook. Whether we're building a prototype for a major product like Timeline at a Hackathon, creating a smarter search algorithm, or tearing down walls at our new headquarters, we're always hacking to find better ways to solve problems," Facebook said in its Hacker's Cup page. 

Facebook said that those who registered for a previous year are automatically registered for the competition year, however, they still need to check their information is up-to-date.