I have heard this in context of a kidnapping and asking a question only you will know the answer too.
The best solution to tell an imposter is by talking about a shared memory but changing some obvious details. You proof you are you by knowing the specific memory, they proof who they are by calling out the wrong detail.
Of course in context of a full clone, they would also have your memory and no amount of planning will help.
I have heard this in context of a kidnapping and asking a question only you will know the answer too.
The best solution to tell an imposter is by talking about a shared memory but changing some obvious details. You proof you are you by knowing the specific memory, they proof who they are by calling out the wrong detail.
Of course in context of a full clone, they would also have your memory and no amount of planning will help.
I always worried about something like that because I have a terrible memory
How did you know that this is my secret decency check to judge people?
If people would not get along with an imaginary clone of themselves its a sign to stay clear of them.
Doesn’t have to be a story - favorite food with the wrong seasoning/condiment could work too; favorite character on show (mismatch as you like), etc.
If it’s a full clone, then they either have the existing moral framework to not betray you or their betrayal was inevitable regardless of the cloning.