159. Few Defence IT systems presently employ asymmetric cryptographic algorithms and their future use is dependent upon the approval of algorithms for Defence use and the existence of suitable implementations. Therefore there is little possibility of standardising an asymmetric key distribution service within the NISP (although open standards for such services, and widely used implementations of commercial algorithms, do exist). There are no acceptably open standards for the distribution of symmetric encryption keys (other than in conjunction with a wider asymmetric distribution service).

160. Clearly, however, if widespread use is to be made of cryptographically-delivered security services within other NISP services (notably messaging), there will ultimately be a requirement to standardise key distribution services. Progress on this front within the NISP is contingent upon current NATO security architecture work.