The disclosure relates to devices and methods implementing polar codes. For instance, the disclosure relates to an an encoder for encoding data, wherein the encoder comprises a processor configured to encode the data using a (n, k, d) parent polar code C into codewords c0n-1=u0n-1A subject to the constraints u0n-1VT=0, wherein u0n-1 denotes the data, wherein A = ( 1 0 1 1 ) ⊗ m , wherein F⊗m denotes the m-times Kronecker product of the matrix F with itself and wherein the constraint matrix V comprises in addition to the constraint matrix V0 of the parent polar code the constraint matrix V1 of a first helper code C1 and the constraint matrix V2 of a second helper code C2.