Rancang Bangun Implementasi Aplikasi Single Sign On pada Sistem Pembelajaran dan Sistem Informasi Berbasis Web

Elearning and web based information systems is a means to communicate and exchange information for academic purposes.  Nowadays lightweight directory access protocol (LDAP) is a state of the art method of choice. With LDAP technologies user only need one username and password to access to multiple web based application, The problem is if the user wanted to do autentification said user had to input their credentials over and over again for each application. To solve that problem single sign on mechanism (SSO) is invented. With SSO user only need login once and they got all the same credentials with them to all intergrated application wthin the campus. To implement the SSO we use Central authentication service (CAS) as a authentifiation central within LDAP structure as a user management. In this reseach we see that single sign on (SSO) system that intergrated into student management system, E-Learning system and  Internal blog system both use of database based system or even LDAP based system

Secure single sign-on schemes constructed from nominative signatures

Single Sign-on (SSO) allows users to only log on once and then access different services via automatic authentication by using the same credential. However, most existing SSO schemes do not satisfy security notions or require a high trust level on a trusted third party (TTP), even though SSO has become popular in new distributed systems and computer networks. Motivated by this fact, we formalise a new security model of single sign-on, which not only satisfies strong security notions but also has a low trust level on TTP. We then propose a generic construction of SSO from nominative signatures, and present concrete initialisation. We also provide formal proofs to show that the proposed SSO scheme is secure according to our new formal model, if the underlying nominative signature is secure. We note that this is the first study that investigates the link between SSO and nominative signatures, which also be of an independent interest

暗号要素技術の一般的構成を介した高い安全性・高度な機能を備えた暗号要素技術の構成

Recent years have witnessed an active research on cryptographic primitives with complex functionality beyond simple encryption or authentication. A cryptographic primitive is required to be proposed together with a formal model of its usage and a rigorous proof of security under that model.This approach has suffered from the two drawbacks: (1) security models are defined in a very specific manner for each primitive, which situation causes the relationship between these security models not to be very clear, and (2) no comprehensive ways to confirm that a formal model of security really captures every possible scenarios in practice.This research relaxes these two drawbacks by the following approach: (1) By observing the fact that a cryptographic primitive A should be crucial for constructing another primitive B, we identify an easy-to-understand approach for constructing various cryptographic primitives.(2) Consider a situation in which there are closely related cryptographic primitives A and B, and the primitive A has no known security requirement that corresponds to some wellknown security requirement (b) for the latter primitive B.We argue that this situation suggests that this unknown security requirement for A can capture some practical attack. This enables us to detect unknown threats for various cryptographic primitives that have been missed bythe current security models.Following this approach, we identify an overlooked security threat for a cryptographic primitive called group signature. Furthermore, we apply the methodology (2) to the “revocable”group signature and obtain a new extension of public-key encryption which allows to restrict a plaintext that can be securely encrypted.通常の暗号化や認証にとどまらず, 複雑な機能を備えた暗号要素技術の提案が活発になっている. 暗号要素技術の安全性は利用形態に応じて, セキュリティ上の脅威をモデル化して安全性要件を定め, 新方式はそれぞれ安全性定義を満たすことの証明と共に提案される.既存研究では, 次の問題があった: (1) 要素技術ごとに個別に安全性の定義を与えているため, 理論的な体系化が不十分であった. (2) 安全性定義が実用上の脅威を完全に捉えきれているかの検証が難しかった.本研究は上記の問題を次の考え方で解決する. (1) ある要素技術(A) を構成するには別の要素技術(B) を部品として用いることが不可欠であることに注目し, 各要素技術の安全性要件の関連を整理・体系化して, 新方式を見通し良く構成可能とする. (2) 要素技術(B)で考慮されていた安全性要件(b) に対応する要素技術(A) の安全性要件が未定義なら, それを(A) の新たな安全性要件(a) として定式化する. これにより未知の脅威の検出が容易になる.グループ署名と非対話開示機能付き公開鍵暗号という2 つの要素技術について上記の考え方を適用して, グループ署名について未知の脅威を指摘する.また, 証明書失効機能と呼ばれる拡張機能を持つグループ署名に上記の考え方を適用して, 公開鍵暗号についての新たな拡張機能である, 暗号化できる平文を制限できる公開鍵暗号の効率的な構成法を明らかにする.電気通信大学201