XSF Discussion - 2024-01-29


  1. topgun

    Hi, is there a proposal for encryption in XMPP which is quantum proof and still with forward secrecy?

  2. jonas’

    there are few cryptographers in our community, so if anything, we'd be using stuff someone else already defined

  3. jonas’

    unless MLS is going to be quantum proof, I cannot see anything in that regard on the horizon.

  4. topgun

    I mean not only for transport but also for storage, like omemo

  5. jonas’

    (omemo has nothing to do with storage)

  6. topgun

    But If I encrypt with omemo, people/servers who are storing my messages, and also clients which store then, cannot read it unless they are intended by me to do so. That's what I mean

  7. jonas’

    OMEMO only protects transit

  8. mathieui

    jonas’: "storage" in the MAM archive

  9. Menel

    If the attacker didn't see the key exchange, only the files on disk at a later time, then it is save. Symmetrical encrypted is already quantum secure. Only the assymetric key exchange is *maybe* *hypothetically* *if quantum processor is really fast* vulnerable.

  10. r00tobo

    does that mean any file I send with http file upload is not encrypted inside the server storage ?

  11. Menel

    If you use omemo, then it is encrypted with a quantum secure encryption™️ on disk

  12. Menel

    (aes)

  13. r00tobo

    so server operator can't see/read the file on the server ?

  14. Menel

    Yes

  15. Menel

    The key to decrypt is only shares with your peer over omemo

  16. Menel

    Not uploaded with the file

  17. Menel

    https://xmpp.org/extensions/xep-0454.html

  18. jonas’

    mathieui, MAM archive is in transit :-)

  19. mathieui

    true

  20. topgun

    > If the attacker didn't see the key exchange, only the files on disk at a later time, then it is save. Symmetrical encrypted is already quantum secure. > Only the assymetric key exchange is *maybe* *hypothetically* *if quantum processor is really fast* vulnerable. What's the name of the algorithm XMPP uses for quantum proof encryption?

  21. Menel

    I talked about AES256 topgun

  22. Menel

    That's what the payload is encrypted with, in omemo

  23. Menel

    And for the file upload....

  24. topgun

    And for assymetric crypto, which algo is quantum resistant?

  25. Menel

    Non, as was already discussed and answered some messages above

  26. Menel

    None in use here, I meant. There are many ideas, unrelated to xmpp. https://en.wikipedia.org/wiki/Post-quantum_cryptography

  27. jonas’

    mathieui, why I'm insisting on "in transit" is that the OMEMO architecture with its forward secrecy basically makes it impossible to also use it for local (client-side) storage of messages. Which is another risk of exposure you need to take into account if you already worry about quantum.

  28. jonas’

    (unlike OX encryption for instance)

  29. middle East

    Hello

  30. topgun

    Hi

  31. root

    Hello

  32. Trung

    Chào

  33. blue

    Just in case: Is there anyone interested in helping out with a c++ qt desktop messenger?

  34. meson

    blue: aka Kaidan?

  35. blue

    no, unfortunately not. The project is called Squawk (https://git.macaw.me/blue/squawk), it's QWidget based

  36. emus

    blue: btw. have you listed it the xsf software.json?

  37. blue

    no, didn't yet, feel a bit ashamed to do it at it's current upstream stage)

  38. emus

    I think no one will blame or or say something. But I think its important to list activities