Patent ID: 8566597
Filing Date: 2013-10-22
Classification: H04L

Abstract:
1. A non-transitory computer-readable medium storing therein a digital signature program that causes a computer to execute a process comprising: acquiring in order of input, a series of input data that are successively input; calculating a unique value for the acquired input data or for target data, by substituting the input data or the target data into a one-way function; judging whether a target area selected from among a storage area group assigned priority ranks is empty; storing the unique value calculated for the input data or for the target data to the target area, when the target area is judged to be empty at the judging; setting newly as the target data, a concatenated unique value concatenating the unique value stored in the target area and, the unique value that is of the input data and not yet stored in the target area or the unique value that is of the target data and not yet stored in the target area, when the target area is judged to not be empty at the judging; selecting from the storage area group and as the target area, the storage area having the highest priority rank, when the unique value of the input data is calculated, and when the target area is judged to not be empty at the judging, newly selecting as the target area, the storage area having the highest priority rank after the storage area previously selected as the target area; and determining based on the number of unique values stored in the storage area group after acquisition of the series of input data, a unique value to be a generation origin of a digital signature for the series of input data.