ELECTRONIC SIGNATURE PROGRAM, ELECTRONIC SIGNATURE DEVICE, AND ELECTRONIC SIGNATURE METHOD

摘要

In (A), when input data (f0) is loaded, a hash value (h0) is calculated and is stored into a memory region (M1) having the highest priority. In (B), when input data (f1) is loaded, a hash value (h1) is calculated. Since the hash value (h0) has already been stored in the memory region (M1), the hash value (h0) is read from the memory region (M1) and the memory region (M1) is emptied. The read hash value (h0) and the hash value (h1) are then combined as a combined hash value (h0|h1). A hash value (h0,1) is then calculated and stored into a memory region (M2) having the second highest priority next to that of the memory region (M1). In (C), when input data (f2) is loaded, a hash value (h2) is calculated and is stored into the memory region (M1) having the highest priority among the five memory regions.