BlackBerry Ltd. said NATO approved its BB10 smartphones for “restricted” security level use. “The certification allows agencies in NATO countries in all 28 member states across North America and Europe to use BlackBerry 10 smartphones in the office or in the field,” BlackBerry said in a release Tuesday. BlackBerry is working to convince enterprise clients to stick with the Waterloo, Ont.-based mobile device maker after it reported a possible sale and second-quarter loss of $965 million US last week. Security is a top-selling feature of the BlackBerry platform and network as the company leaves the consumer market to serve business clients only. "We built the new BlackBerry 10 platform from the ground up with the highest security needs of our government and enterprise customers in mind," Scott Totzke, senior vice-president of security at BlackBerry, said in the release. "The fact that BlackBerry Enterprise Service 10 and BlackBerry 10 smartphones have been approved for classified communications just months after debut, is testament to the thoroughness of its design and our commitment to our defense and government customers,” he said. BlackBerry's BB10 enterprise service uses end-to-end security and AES 256-bit encryption for data at rest and in transit, the release said.