Predict math.random(0) last bit

[Albert Chan <albertmcchan@...>]

 

On Mar 23, 2018, at 6:31 PM, Coda Highland <chighland@gmail.com> wrote:

> 

> if you see the least significant bit of 128 consecutive calls to 

> math.random, then you can predict the least significant bit of every 

> call from there on out.

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I think above statement is only half-right.

Above statement is true ONLY if we already solved

the 128 coefficient of LSFR.

To solve for the coefficients, we need 256 calls.

-> 128 equations with 128 unknown (coefficient)

http://practicalcryptography.com/cryptanalysis/modern-cryptanalysis/lfsrs-and-berlekampmassey-algorithm/