Direct proofs of the undecidability of the equivalence problem for sentential forms of linear context-free grammars and the equivalence problem for OL systemsG. Rozenberg · 1972

Power languages and densityValtteri Niemi · 1991

Secure multiparty computations without computersValtteri Niemi; Ari Renvall · 1998

Trends in mobile security standardsValtteri Niemi · 2004

Editorial for the LTE special sectionValtteri Niemi · 2010

Distributed Usage ControlDebmalya Biswas; Nikolai Nefedov; Valtteri Niemi · 2011

Distributed and minimal usage controlDebmalya Biswas, Nikolai Nefedov, Valtteri Niemi · Service Oriented Computing and Applications · 2012

Fragmentation algorithms for DTN linksGinzboorg, Philip; Niemi, Valtteri; Ott, Jörg · Computer Communications · 2013

Density of grammar forms part IINiemi, Valtteri · International Journal of Computer Mathematics · 1986