Chinese President Xi Jinping gifted South Korean President Lee Jae Myung a pair of smartphones, jokingly telling him to 'check if there's a backdoor' — referring to the risk of unauthorized bypassing of security controls. Andrew Chang breaks down the layers of Xi's comment to better understand what may have been hidden behind the humour. 1:07 - Security signals 4:26 - The open secret of spycraft Images provided by The Canadian Press, Reuters and Getty Images »»» Subscribe to CBC News to watch