Cross-Border e-Government Authentication Services. - Alexandros B. Sideridis; Constantina I. Costopoulou; Costas P. Yialouris; Ioannis Savvas; Michael T. Maliappis; Maria Ntaliani; Sotiris Karetsos; Stergios G. Tsiafoulis; Loucas Protopappas; Andreas Chatziandreou (HAICTA, 2017)