A novel off-line algorithm and a modified chain code for recognizing signatures are proposed in the present study. Carbon paper is used to detect force distributions when people write their signatures. First of all, the signature contours are located and the upper and lower profiles are generated; then, these are used to classify the given signature. Both the gray-scale and the chain code characteristics of a signature are used to extract structure and force distribution features, which are then transformed into a normalized vector. Finally, a Supervised Fuzzy Adaptive Hamming Network (SFAHN) is employed to interpret the feature vector in order to determine whether the signature is genuine or not. Simulation results show that the proposed algorithm has a good recognition rate.