Anonymous encryption with partial-order subset delegation and its application in privacy email systems

• Published in: IET information security 2014-07, Vol.8 (4), p.240-249
• Main Authors: Zhang, Mingwu, Nishide, Takashi, Yang, Bo, Takagi, Tsuyoshi
• Format: Article
• Language: English
• Subjects: adaptive chosen‐plaintext attacks; adaptive chosen‐subset attacks; anonymous encryption scheme; Applied sciences; computational delegation indistinguishability; Computer information security; Computer science; control theory; systems; Cryptography; data privacy; Electronic mail; Email; email privacy systems; Encryption; Exact sciences and technology; fine‐grained key delegation; fine‐grained security; Information, signal and communications theory; interdisciplinary group email management system; Memory and file management (including protection and security); Memory organisation. Data processing; message confidentiality; Messages; partial‐order subset delegatable ability; partial‐order subset delegation; Privacy; privacy‐carrying email systems; private key cryptography; public key cryptography; receiver anonymity; Receivers; secure email systems; Security; Signal and communications theory; Software; Telecommunications and information theory
• ISSN: 1751-8709; 1751-8717; 1751-8717
• DOI: 10.1049/iet-ifs.2013.0045

In privacy-carrying email systems, the authors should guarantee that the email content is confidential and sometimes the sender/receiver identities are hidden. Also, they require that the key generation is flexible and manageable. In this study, first, they propose an anonymous encryption scheme that supports a partial-order subset delegatable ability. The proposed scheme achieves the security properties of confidentiality against adaptive chosen-plaintext attacks, anonymity against adaptive chosen-subset attacks and computational delegation indistinguishability. Secondly, they provide a deployment application of their anonymous encryption in an interdisciplinary group email management system with flexible and fine-grained key delegation. The deployment can achieve the privacy of message confidentiality, receiver anonymity and delegation obliviousness, which has fine-grained security in secure email systems. Finally, they provide an extension for the chosen-ciphertext secure scheme, and discuss the efficiency for decryption and the security level.