2 ms·
... at which point you lose the whole "something you have" part of 2FA. If they all have the same key, it is impossible to distinguish between individual copies
by crote 1y ago
... at which point you lose the whole "something you have" part of 2FA. If they all have the same key, it is impossible to distinguish between individual copies, so the compromise of a single copy is impossible to detect. Additionally, you can't revoke a single copy: you are now forced to revoke all of them at once.