Abstract: The quantum walk search algorithm on the hypercube has been an important milestone in the study of quantum walks. The algorithm can be used to find the marked vertex of the hypercube, and solves the problem in time proportional to the square root of the size of the search space. The efficiency of this algorithm is only a constant factor less than that of the Grover's search. The first part of the talk is focussed on the efficiency of the hypercube search algorithm subject to errors typical for an optical implementation. A universal law for the dependence of efficiency is also presented. In the second part, modifications that establish an equivalence with the Grover's algorithm in terms of complexity is presented.