Cellular Network Infrastructure » IMSI Pseudonymization

As discussed in the weekly telcos, the draft specification does not need to contain the exact references to ETSI specifications that would need to be changed (unlike I had assumed when creating this issue). So the following document should be enough as draft specification, it describes in detail how the IMSI pseudonymization will work:

https://gerrit.osmocom.org/plugins/gitiles/imsi-pseudo/+/refs/heads/master/README.md

laforge: when you have time, can you read through it and confirm that this issue can be closed (that we have completed that milestone)?

osmith wrote:

https://gerrit.osmocom.org/plugins/gitiles/imsi-pseudo/+/refs/heads/master/README.md

laforge: when you have time, can you read through it and confirm that this issue can be closed (that we have completed that milestone)?

I think this document currently only works for a reader who has a very detailed understanding of what this project is all about before reading it.

• ensure that the document calls itself a specification
• include a specification version, author, date.
• include a status (DRAFT)
• start at a higher level, such as describing how the procedures work in the normal network
• also describe why the transmission of the IMSI over the radio interface (or to the visited operator) is a problem at all (separately for each case)
• include ladder diagrams or other illustrations to show the flow of events

Particularly once you start, I think this really should become an asciidoc document. It also provides the infrastructure for versions/authors/status/...

Furthermore, it has the advantage that we could later merge [parts of] it to the osmo-hlr manual.

Would be good to work on this soon-ish, as we cannot complete our first milestone (and invoice) without it.

I've created the proper specification draft with asciidoc in the git repository, and attached the PDF to this issue.

laforge: please have another look.

laforge wrote:

I've pushed some minor changes, please review if they seem OK to you.

Yes, they are fine.

Some open topics, from my point of view:
[...]

All changes applied, please review again.

Later on, we should also think of:

• consider which parts we consider mandatory (the general principle) and which
  optional (the exact binary format of the SMS, which is just an implementation detail and
  doesn't really matter to achieving the desired functionality)

=> #4489

• consider how IMSI-pseudo would interact within a combined (2G-4G)+5G network,
  whereas the latter already solves the problem by means of the SUCI.

=> #4490

Finished draft pdf is linked in the wiki now: https://osmocom.org/projects/imsi-pseudo/wiki