Portability must be included as part of a thoroughgoing review/rewrite of the section of eduPerson (200806) on "Identifier Concepts:"
1) uniqueness
2) persistence
2a) reassignable
3) mutable
3a) resynchable
4) palatable
5) opacity
6) correlatable
7) privacy
8) portable
Many of these properties need to have more possible values than True or False.
[Few of the properties] are properties of the identifiers themselves, most are properties of the use of the identifiers in the context of many interacting systems.
Look at reassignment. It has to do with practices at the IdP, whether an identifier continues to apply to the same entity or can be used for a different one. The identifier stays the same, it's the mapping to the "real world entities" that might change. So the model needs to include those entities, the IdM system that maintains (or doesn't) the mapping, and the interest of the RP in the continuity of the mapping.
Here's a trial run with further revisions (dependency is indicated by indentation)
From perspective of the University of Wisconsin-Madison as IdP
Properties of Identifier Usage |
ePPN |
UUID |
PVI |
ePTID |
|---|---|---|---|---|
– Scope |
wisc.edu |
wisc.edu |
wisc.edu |
wisc.edu |
|
within scope |
global |
within scope |
global |
– Reversible |
reversible |
reversible |
reversible |
reversible |
– Persistence |
persistent |
persistent |
persistent |
persistent |
– Transparency |
transparent |
opaque |
opaque |
opaque |
|
palatable |
no |
palatable |
no |
– Mutable |
mutable on approved user request |
mutable only in case of mistaken identity |
mutable only in case of mistaken identity |
mutable |
|
potentially |
no |
potentially |
no |
|
resynchable |
no |
no |
resynchable |
– Correlatable |
correlatable |
correlatable |
correlatable |
only within specific application group |
– Portable |
no |
potentially |
no |
no |
NOTE: Name identifiers are a threat to privacy to the extent that they are transparent, reversable, resynchable,
correlatable and portable