@article{oai:ipsj.ixsq.nii.ac.jp:00176446, author = {Dai, Watanabe and Hisao, Sakazaki and Kunihiko, Miyazaki and Dai, Watanabe and Hisao, Sakazaki and Kunihiko, Miyazaki}, issue = {12}, journal = {情報処理学会論文誌}, month = {Dec}, note = {In this paper we consider the (legal) representative in governmental ICT services and propose a secure private mail box system in which a message sent to the pupil is re-encrypted by the proxy server. This process enables the representative to decrypt the message. We also show its formal description of the protocols and evaluate the security by ProVerif model checking tool. ------------------------------ This is a preprint of an article intended for publication Journal of Information Processing(JIP). This preprint should not be cited. This article should be cited as: Journal of Information Processing Vol.25(2017)(online) ------------------------------, In this paper we consider the (legal) representative in governmental ICT services and propose a secure private mail box system in which a message sent to the pupil is re-encrypted by the proxy server. This process enables the representative to decrypt the message. We also show its formal description of the protocols and evaluate the security by ProVerif model checking tool. ------------------------------ This is a preprint of an article intended for publication Journal of Information Processing(JIP). This preprint should not be cited. This article should be cited as: Journal of Information Processing Vol.25(2017)(online) ------------------------------}, title = {Representative System and Security Message Transmission using Re-encryption Scheme Based on Symmetric-key Cryptography}, volume = {57}, year = {2016} }