| CPC G06F 21/602 (2013.01) [G06F 7/588 (2013.01); G06F 7/764 (2013.01); G06F 21/31 (2013.01); H04L 2209/46 (2013.01)] | 20 Claims |

|
1. An information processing apparatus comprising:
at least a processor; and
a memory in circuit communication with the processor,
wherein the processor is configured to execute program instructions stored in the memory to implement:
a data storage part that stores a share that is secret, the share shared among four apparatuses including the information processing apparatus;
a basic operation seed storage part that stores a seed for generating a random number used in computing the share;
a reshare value computation part that generates the random number using the seed, computes a reshare value of the share using the generated random number, and transmits data regarding the generated random number to other of the four apparatuses; and
a share construction part that converts the share to a type-converted share while maintaining a share format before and after conversion, using the data regarding the generated random number and the reshare value as received from the other of the four apparatuses.
|