The artist's name on the poster is not indicated. By assigning Artist Unknown to a poster it also could mean the artist used a chop mark whereby no signature is seen thus rendering the artist's identity anonymous.
VEB means "Volkseigener Betrieb", a People's Enterprise (i.e., Government owned)
Deutsche Werbe und Anzeigengesellschaft (DEWAG) was the East German state advertising agency responsible for ideology and the implementation of advertisement regulations. It was formed as a private entity in 1945 and handled advertising for commerce in East Germany as well as overseeing propaganda posters and banners for the Socialist Unity Party, the Marxist–Leninist political party of the German Democratic Republic or, DDR.