EncryptedParts

The section EncryptedParts tells which part of the message should be encrypted.
<sp:EncryptedParts xmlns:sp="http://schemas.xmlsoap.org/ws/2005/07/securitypolicy">
  <sp:Body />
Encrypt the body using the algorithm referenced in assertion AlgorithmSuite:

To find the exact syntax of security message read the specifications "Web Services Security: SOAP Message Security 1.0".