A method and structure of processing soft information in a block code decoder, includes a soft-input soft-output decoder receiving a length n soft input vector, creating a binary vector Y corresponding to the soft input vector, hard decoding each linear function Xi of Y and a test pattern Zi of one or more test patterns, wherein if the hard decoding is successful a codeword produced by the hard decoding of Xi is added to a set S, removing redundant codewords in S to form a reduced set S′ based on processing a number of errors found during the hard decoding and a guaranteed error correcting capability of the block code decode, and an extrinsic value estimator generating n soft outputs based on c estimated soft output values and (n-c) non-estimated soft output values wherein the c estimated soft output values are computed from one or more positions of soft input vector and one or more codewords in S′.