Let r, B and w be positive integers. Let C be a linear code of length Bw and subspace of Fr 2. The k-regular-decoding problem is to find a nonzero codeword consisting of w length-B blocks with Hamming weight k. This problem was mainly studied after 2002. Not being able to solve this problem is critical for cryptography as it gives a fast attack against FSB, SWIFFT and learning parity with noise. In this paper, the classical methods are used in the same algorithm and improved.