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seen Jul 12 at 18:15

Mar
15
asked Trying to calculate the strength of a Bitcoin brain wallet created with a custom diceware password
Jun
10
comment Is this OTP scheme safe?
@StephenTouset What could be unsafe is that I used the keys more than once (one time to create c1 , another time to create c2), so it doesn't meet all the requirements for being an actual OTP, and therefore it's not theoretically unbreakable anymore. But I could be wrong.
Jun
10
awarded  Commentator
Jun
10
accepted Is this OTP scheme safe?
Jun
10
comment Is this OTP scheme safe?
Perfect, thanks a lot!
Jun
10
revised Is this OTP scheme safe?
deleted 81 characters in body
Jun
9
comment Is this OTP scheme safe?
@StephenTouset I won't before knowing the answer to this question: is this safe?
Jun
9
comment Is this OTP scheme safe?
@StephenTouset I don't want to have to forge it when I'm forced, I need to have it prepared beforehand. That's why I want to know whether I'm spoiling the security (and to what degree) by reusing the keys, even if it is for a fake message.
Jun
9
comment Is this OTP scheme safe?
@StephenTouset But that's only if I have access to all 3 parts in the first place. Normally I won't. I will keep only 1, and give the other two to other parties.
Jun
9
comment Is this OTP scheme safe?
@StephenTouset When they ask for the 3 parts needed to reconstruct m1, I won't hand over k1, k2, and c1. I will hand over k1, k2, and c2, and they will reconstruct m2, which is the fake message.
Jun
8
revised Is this OTP scheme safe?
added 81 characters in body
Jun
8
revised Is this OTP scheme safe?
added 13 characters in body
Jun
7
revised Is this OTP scheme safe?
added 116 characters in body
Jun
7
comment Is this OTP scheme safe?
@Thomas I wanted to give each K to a different party to keep them safe, so I need them separated to better understand the problem. But yes, I should learn the notation.
Jun
7
comment Is this OTP scheme safe?
About your second point: I should have specified that each key is going to be given to a different party. It's a 3-of-3 scheme, where you need to recover all 3 parts to reconstruct the message.
Jun
7
comment Is this OTP scheme safe?
You are right. Maybe I should have specified that M1 and M2 are both gone after the encryption, since that's why I'm using encryption in the first place: to protect the message.
Jun
7
revised Is this OTP scheme safe?
added 144 characters in body
Jun
7
asked Is this OTP scheme safe?
Jun
6
awarded  Student
Jun
5
awarded  Scholar