The called container must verify the correspondence between the call request and the attached message signature, and compute and attach a message signature to the call response. The performance cost associated with applying integrity protection to all message communication is as much a property of the operational environment as it is a consequence of the cost of the protection. One way to safeguard the integrity of application messages without unnecessarily limiting the space of operational environments, is to capture application-specific knowledge identifying which messages must be integrity protected. The place to capture this information is in the application's deployment descriptor. Confidentiality Mechanisms Confidentiality mechanisms ensure that communication between entities is kept private.
Privacy is achieved by encrypting the message contents.
The Deployer is responsible for configuring containers to apply confidentiality mechanisms to ensure that sensitive information is not disclosed to third parties. Despite the improved performance of the shared secret mechanisms, the costs of message encryption are significant, and should be expected to have an adverse effect on performance when confidentiality mechanisms are applied where they are not needed. The Application Assembler should supply the Deployer with information on which method calls of which components feature parameters or return values that should be protected for confidentiality. The Deployer then must configure the containers involved in a call to employ a confidentiality mechanism whenever one of the method calls identified by the Application Assembler will traverse open or unprotected networks. In addition to applying confidentiality mechanisms where appropriate, the Deployer should configure containers to reject call requests or responses with message content that should be protected but isn't protected.