http://www.thedialogcenter.com/EncryptionService.wsdl 

##</code><code>##

  print SOAP::Lite
    -> uri('http://www.arkbluecross.com/WebServices/EncryptionService/Encrypt')
    -> service('http://thedialogcenter.com/EncryptionService.wsdl')
    -> Encrypt('43877AF844D640A189E5708F3BE9222E', 'Testing');

##</code><code>##

->proxy() instead of ->service()