Dealers, key servers, and restorers

摘要

To suppress memory capacity.SOLUTION: k-1 equations are prepared on the basis of fundamental equations in order to obtain k-1 unknowns from a value obtained on the basis of key data held in k-1 key servers within n servers, the k-1 unknowns, and IDs of the key servers; the k-1 unknowns are obtained from the prepared equations; and a value determined according to the obtained k-1 unknowns and the remaining n-(k-1) data servers within the n servers, and dispersion values for dispersing to each of the n-(k-1) data servers on the basis of the fundamental equations, are calculated and held in each data server. Accordingly, it is not necessary to save the dispersion values in the n data servers, and therefore memory capacity can be suppressed.SELECTED DRAWING: Figure 6