Polycyclic groups: A new platform for cryptology?
  We propose a new cryptosystem based on polycyclic groups. The cryptosystem is based on the fact that the word problem can be solved effectively in polycyclic groups, while the known solutions to the conjugacy problem are far less efficient. 
Bettina Eick (TU Braunschweig), Delaram Kahrobaei (University of St   Andrews)