2022-08-08T05:00:44Zhttps://ipsj.ixsq.nii.ac.jp/ej/?action=repository_oaipmhoai:ipsj.ixsq.nii.ac.jp:001863252020-04-01T00:33:29Z01164:02836:09354:09427
A Certificateless Signature Scheme to Reduce Loads on Key Generation CenterA Certificateless Signature Scheme to Reduce Loads on Key Generation Centerenghttp://id.nii.ac.jp/1001/00186237/Technical Reporthttps://ipsj.ixsq.nii.ac.jp/ej/?action=repository_action_common_download&item_id=186325&item_no=1&attribute_id=1&file_no=1Copyright (c) 2018 by the Information Processing Society of JapanOsaka UniversityOsaka University／NICTOsaka UniversityNAIST／Osaka UniversityOsaka UniversityOsaka UniversityEi, Khaing WinYuuichi, TeranishiYoshimasa, IshiTomoya, KawakamiTomoki, YoshihisaShinji, ShimojoCertificateless public key cryptography (CLPKC) eliminates the certificate and avoids key escrow problem. In CLPKC, Key Generation Center (KGC) is responsible for generating partial private key and revoking a user is an important problem. There have been some solutions to revoke users in CLPKC. Though an existing solution proposes a pairing-free revocation scheme, it still requires high time key computation cost of exponentiation operations on KGC. In this paper, we propose a revocable certificate-less signature scheme which requires less computation cost than existing schemes. In the proposed scheme, valid users receive the time key, which is calculated using only one exponentiation operation and some hash operations on KGC for a revocation. Under the discrete logarithm problem assumption, we prove that the proposed scheme is secure against existential forgeability in the random oracles.Certificateless public key cryptography (CLPKC) eliminates the certificate and avoids key escrow problem. In CLPKC, Key Generation Center (KGC) is responsible for generating partial private key and revoking a user is an important problem. There have been some solutions to revoke users in CLPKC. Though an existing solution proposes a pairing-free revocation scheme, it still requires high time key computation cost of exponentiation operations on KGC. In this paper, we propose a revocable certificate-less signature scheme which requires less computation cost than existing schemes. In the proposed scheme, valid users receive the time key, which is calculated using only one exponentiation operation and some hash operations on KGC for a revocation. Under the discrete logarithm problem assumption, we prove that the proposed scheme is secure against existential forgeability in the random oracles.AN10116224研究報告マルチメディア通信と分散処理（DPS）2018-DPS-17421162018-02-262188-89062018-02-26