For the protection of the transfer of information between HiMoNN nodes the as secure widely accepted and powerful IPSec encryption standard was used and adapted to the requirements of a mobile ad-hoc system. In this context the application of SINA technology was also successfully tested with HiMoNN in co-operation with the BSI and the secunet Security Networks AG. SINA is a secunet product and is the only IP-based technology for the transfer of classified information up to the classification TOP SECRET certified by the BSI.