Listing1.cs

public class MessageSecurityBehavior:IEndpointBehavior
{
    public ProtectionLevel ProtectionLevel { get; set; }


    public void ApplyClientBehavior(ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.ClientRuntime clientRuntime)
    {
        //Do nothing
    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.EndpointDispatcher endpointDispatcher)
    {
    //Do nothing
    }

    public void Validate(ServiceEndpoint endpoint)
    {
    //Do nothing
    }

    public void AddBindingParameters(ServiceEndpoint serviceEndpoint, BindingParameterCollection parameters)
    {
        //Setting the ProtectionLevel at the Service Contract
        serviceEndpoint.Contract.ProtectionLevel = ProtectionLevel;

        parameters.Remove<channelprotectionrequirements>();

        ChannelProtectionRequirements requirements = new ChannelProtectionRequirements();
        parameters.Add(requirements);

        MessagePartSpecification unprotectedBody = new MessagePartSpecification();
        MessagePartSpecification protectedBody = new MessagePartSpecification(true);

        switch (ProtectionLevel)
        {
            case ProtectionLevel.None:
                requirements.OutgoingSignatureParts.AddParts(unprotectedBody, "*");
                requirements.IncomingSignatureParts.AddParts(unprotectedBody, "*");
                requirements.OutgoingEncryptionParts.AddParts(unprotectedBody, "*");
                requirements.IncomingEncryptionParts.AddParts(unprotectedBody, "*");
                break;
            case ProtectionLevel.Sign:
                 requirements.OutgoingSignatureParts.AddParts(protectedBody, "*");
                 requirements.IncomingSignatureParts.AddParts(protectedBody, "*");

                 requirements.OutgoingEncryptionParts.AddParts(unprotectedBody, "*");
                 requirements.IncomingEncryptionParts.AddParts(unprotectedBody, "*");
                 break;
             case ProtectionLevel.EncryptAndSign:
                 requirements.OutgoingSignatureParts.AddParts(protectedBody, "*");
                 requirements.IncomingSignatureParts.AddParts(protectedBody, "*");
                 requirements.OutgoingEncryptionParts.AddParts(protectedBody, "*");
                 requirements.IncomingEncryptionParts.AddParts(protectedBody, "*");
                 break;
         }
    }     
}