Facebook said on Tuesday it would start allowing users to set up physical security keys as a way to verify their identity before logging into the social network’s mobile app, beginning next year. The company currently offers an option to require a hardware security key to connect to a desktop computer before each log-in. Users could purchase a hardware key from retailers, and register it with Facebook, the company said, confirming an earlier report by news website Axios. The world’s largest social network said it also plans to expand Facebook Protect—its security program for high-profile accounts including election candidates—to more types of accounts globally next year. The rollout of new security services follows a July hack of peer social network Twitter Inc which compromised many celebrity accounts, including those of Democratic nominee Joe Biden and Tesla Chief Executive Officer Elon Musk. Currently available in the United States, Facebook Protect offers …