The present invention aims at providing an encoding device for error correction, encoding method for error correction and encoding program for error correction wherein countermeasures against eavesdropping are taken into account. To achieve this, in accordance with an aspect of the present invention there is provided an encoding device for error correction, the device comprises a generation means for generating randomly a vector u=(xk+1, . . . , xm) composed of m-k digit(s); a creation means for creating an x′=[xu]=(x1, . . . , xm) by concatenating the vector u=(xk+1, . . . , xm) composed of m-k digit(s) randomly created by the creation means to data x=(x1, . . . , xk) to send; and an output means for outputting a vector of length n by carrying out [n, m] encoding of the x′ created by the creation means.