O2 (UK) BT subsidiaries: Esat Digifone in Ireland, Viag Interkom in Germany and Telfort Mobiel in the Netherlands. The rebranding was supported by a European advertising campaign, which began on 16 April 2002, across all four countries, at a cost of £130 million. The main launch campaign ran from 18 June and was developed by Vallance Carruthers Coleman Priest, working alongside brand consultancy Lambie-Nairn, creators of the "O2" brand identity. In March 2005, mmO2 restructured its shares and the company was relisted as O2 plc. On 30 November 2005, O2 agreed to a takeover by Telefónica, a Spanish telecommunications company, for £17.7
Safelayer Secure Communications Safelayer Secure Communications Safelayer Secure Communications S.A. is a Spanish private company founded in May 1999. It develops software products on the Public key infrastructure area (digital security for the identity management, electronic signature and data protection). Safelayer's technology is part of the three major certification and digital identity projects in Spain: Fábrica Nacional de Moneda y Timbre, the Spanish ID card "DNI electrónico" and the Spanish E-passport. Safelayer's technology also secures the NATO X400 messaging system". Safelayer's technology has been and Common Criteria certified. Currently, Safelayer is the only company with a whole family of products CC EAL4+ certified.