Encryption and Decryption

Hi

I am a new user of this Soap tool. I just want to setup an environment where i need to encrypt the outgoing soap message and decrypt the incoming message. I have tried the options avilable in soap
But it is throwing a error message when i am trying add a keystore.
NO private Keys found. what does it mean.
Do we need to have private keys for each keystore entry.
Could you plese guide me in this regards