There is provided an information processing system including: a first apparatus (10a) that divides a user key (UK) of a share-source user through a secret distribution process to generate a plurality of distribution keys (S1 and S2); a second apparatus (10b) that sends a processing request to execute a predetermined process by using one of a plurality of the distribution keys generated by the first apparatus; and a third apparatus (20) that makes a determination based on one of a plurality of the distribution keys generated by the first apparatus and the processing request received from the second apparatus.