The conception of Trusted Network Connection (TNC) is introduced, and the problem of TNC protocol extend is analyzed. Direct Anonymous Attestation (DAA) protocol is descripted. After this, the paper takes out a new host Indentity based One-time Key Exchange Protocol (I-OKEP), and analyzes its security character. The security analysis can prove that the protocol can ensure the confidentiality and reliability of key-exchange, and the integrity and anonymous of host in trusted computing environments.