NTT Assigned Patent

Nippon Telegraph and Telephone Corporation (NTT), Chiyoda-ku, Japan, has been assigned a patent (9,894,056) developed by Kobayashi, Tetsutaro, Yamamoto, Go, and Yoshida, Reo, Tokyo, Japan, for a “segmented secret-key storage system, segment storage apparatus, segmented secret-key storage method.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: “The risk of leakage of secret information caused by leakage of a secret key is reduced. A segmented secret-key storage system segments a secret key SK into segments that can be combined at the time of decryption or at the time of generation of a signature and records the secret-key segments sk.sub.1, . . . , sk.sub.N in segment storage apparatuses. The secret-key segments are changed, periodically or under a predetermined condition, to another set of secret-key segments that satisfies a condition for combination. In the segmented secret-key storage system, the secret key SK is not revealed unless the secret-key segments are stolen from all the segment storage apparatuses in an interval between changes made to the secret-key segments. Accordingly, the risk of leakage can be greatly reduced in comparison with the risk of leakage of the secret key from a single apparatus.”

The patent application was filed on January 16, 2014 (14/760,935).