Number theoretic transform modulo K.2N+1, a prime

Due to its simple and real arithmetic structure Number Theoretic Transform is attractive for computation of convolution. However, there exists a stringent relation between the choice of modulus M and convolution length. Choice of modulus as K.2^N+1, a prime, leads to relaxation of this constraint and wide choices of wordlength, with each of these associated with many choices of convolution length are are obtained. Under these choice of modulus a computational structure when the convolution length is a perfect square is presented.