To ensure the maximum creativity and imagination, the participants want guarantees that nothing they say can be used against them later, and that no commitments can be made inside of the conference. In a competitive market place, the ideas discussed are valuable commodities, and so the media streams should be protected against eavesdroppers. Indeed, the fact that the two companies are talking to each other may be valuable, since it may affect the share prices of the company. The need to ensure that participants can repudiate what they have said is a contradictory requirement from ensuring that the members are authenticated. It can be achieved by sending the data through a trusted third party, who acts as an anonymiser.
Authentication is provided to the third party on both input streams and output streams.
Going further, the third party can help in preventing connectivity leakage by aggregating many traffic streams, and ensuring that there is no mapping between input and out streams.