WSS draft 17 Issue -encryption processing rules clarity

I would like to ask a clarification on the Encryption processing 
rules in the SOAP Message Security Draft 17, 27 August 2003, 
merged

Section 9.3.1 Encryption processing rules, next to last bullet 
(lines 1146-1149) indicates that one KeyInfo element in an EncryptedData element 
may reference another KeyInfo element.

Questions

1. Does this imply the two KeyInfos are in different 
EncryptedData elements? What is the assumption on the two KeyInfos 
location?

2. What is the rationale and driving use case for this? Is it to allow two 
EncryptedData elements to share a key without requiring replication of the key 
information? Is it an alternative to using KeyName?

 

3 What is the mechanism to reference another 
KeyInfo element from another? Is it a SecurityTokenReference or something else? 
Where is this defined as a standard? Does this need to be stated in the WSS 
specification?

 

Assumptions around this processing rule would be 
helpful.

 

Thanks

regards, Frederick

Frederick Hirsch
Nokia Mobile 
Phones