I tried using a card duplication machine, but it complained not supported. The device is Xixei v7, able to clone a mifare card easily, connected to PC to try to decode but not working.
The reader is likely reading the CDN code only, how can I proceed to clone/duplicate encrypted cards like this?
What sort of system is the tag being used for?
It’s a residential which I am staying…
You’re probably out of luck
iClass Seos is one of the more secure credentials out there, you’re not going to be able to copy it. It may be possible to downgrade it to a different card depending on the system. In an extremely unlikely scenario it could be set up to use only the UID, you might be able to copy that to a magic mifare and hope it works
Does the UID change every time you scan the card with NFCTools?
To expand on this, there are some systems where while the readers have been upgraded, there are still legacy cards out there. Think of an office building that’s been around for a long time and they don’t want to bother upgrading all the worker’s cards. The idea is that eventually the system will be more secure because everyone will have secure cards (and the entropy of older cards/users). Downgrade attacks might work, but IMO Seos cards are fairly secure and a major PITA.
