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I'm having trouble figuring out a solution to this problem.
Basically what i am trying to do is create random data that can be repeated across multiple machines by a user but is also secure from attackers.
How i'm tackling this problem now is a user enters a 5 digit pin. That 5 digit pin acts as a rng seed. If the user moves to a different machine, they can re enter that 5 digit pin and the rng output will be the same. This part is important for the system.
This works however the entropy of a 5 digit pin isn't enough to be considered a secure seed. I think what you want to see is 128 bits of entropy. An attacker can easily brute force a 5 digit pin.
Any thoughts as to how i can secure this more. "You can't" is an acceptable answer in my mind. If i need to implement something different than a rng i would appreciate some suggestions.
Thank you all