%%% Compute the Data complexity of the multiple differential cryptanalysis %%%
%%% for a given success probability according to the Corollary 1 of        %%%
%%% BLONDEAU-GERARD FSE 2011. The value of the coef (between 1 and 2)      %%%
%%% depends on the targeted success probability.                           %%%

%%% Parameters:
%%%    pstar: probability $p_*$ for the good key candidate
%%%    p    : probability $p$ for other key candidates
%%%    D0   : number of input differences
%%%    l    : size of the list of kept candidates
%%%    n    : total number of candidates

function res = Nprime(pstar,p,D0,l, n)
coef=1.5;
res = -coef*2 * log(2*sqrt(pi)*l/n) / (D0*Kullback_Bernoulli(pstar,p));
end