A method and apparatus for extending secure communication operations via
shared lists is accomplished by creating a shared list in accordance with
authorization parameters by one user and subsequently accessing the shared
list via the authorization parameters by this and other users. To create
the list, a user within the secured communication system determines
whether it has been enabled, or authorized, to create a shared list. If
so, the user identifies at least one other user to be added to the shared
list. Having identified another user, the user creating the shared list
verifies that the secure communication parameters (which includes a public
key certificate of an end-user or of a certification authority) it has
received regarding the another user is trustworthy. If the secure
communication parameters are identified as trustworthy, the secure
communication parameters of the another user are added to the shared list.
To authenticate the shared list, the user creating the list digitally
signs it. Once the shared list is created, other users, if authorized, may
access the shared list to obtain certificates (e.g., encryption and/or
signature verification certificates) of the users contained in the list.