US Patent Issued to Nippon Telegraph and Telephone on May 27 for "Public key authentication device, public key authentication system, public key authentication method, and program" (Japanese Inventor)

ALEXANDRIA, Va., June 17 -- United States Patent no. 12,316,781, issued on May 27, was assigned to Nippon Telegraph and Telephone Corp. (Tokyo).

"Public key authentication device, public key authentication system, public key authentication method, and program" was invented by Hiromu Aoshima (Musashino, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A device includes: a certificate check unit that, when a public key of a user A in a public key certificate stored in an IC card owned by the user A of a calling-side A telephone set using SIP is read and transmitted by the A telephone set and then received by a SIP server, checks validity of the public key certificate with an authentication server that auth...