ws security policy

["huseyin Davut" <huseyin_davut@hotmail.com>]

I have a question regarding the WS-SecurityPolicy. In the specifications it 
says "a requestor may require that specific portions of a message be 
encrypted and that a specific algorithm be used. For example, a service may 
require the body to be encrypted using triple-DES". My question is what if 
the algorithm is not supported by the source. Also, senders of the message 
may use a confidentiality mechnamism (encryption algorithm) which may not be 
supported by the target. So, my question is how do you determine which 
algorithms will be used.

Many Thanks,

Huseyin