The research on image Information Hiding (IH) algorithm based on error-correcting code is aimed at overcoming poor robustness flaws of spatial domain image information hiding algorithm. The property of correcting random error of the error-correcting code could be used to improve the robustness of spatial domain information hiding algorithm, so that the modifications to the covers by attacker could be effectively resisted. Two different algorithms were proposed: the Least Significant Bit (LSB) information hiding algorithm based on error-correcting code and the gray-bit information hiding algorithm based on error-correction code. By embedding the coding form of secret information in LSB in the first algorithm, relatively high robustness could be achieved in the case of low density noise; while in the second one, by applying the structural characteristics of image pixel gray values, and coding each pixel gray value which had been embedded the secret information in the form of Hamming code, one error could be corrected by each pixel independently. Both theoretical analysis and experimental results show that, under the condition of same density and value of noise, the percentages of secret information recovered of these two algorithms are higher than the basic LSB algorithm, so they are two information hiding algorithms with higher robustness.

Coding cryptography is widespread concerned because it has the advantages of resisting quantum algorithm. To protect the anonymous message, a kind of blind signature scheme based on coding was proposed. By Hash technique and blind factor, message owner sent irreversible and blinding message to the signer, signer completed blind signature by using Courtois-Finiasz-Sendrier (CFS) signature scheme and sent it back to the message owner, message owner obtained signature by blind removing operation. Analysis show that the new scheme not only has the basic nature of general blind signature, but also inherit the advantages of CFS signature scheme such as high security and short signature length, in addition, it can effectively resist attacks of quantum algorithm.