具選擇性屬性撤銷及時效性之屬性加密協定

10.29428/9789860544169.201801.0176

許建隆；鍾孟軒；程冠霖；呂崇富

雲端儲存 ； 屬性加密 ； 金鑰絕緣 ； 時效性 ； 屬性撤銷 ； Cloud Storage ； Attribute-Based Encryption ； Attribute Revocation ； Key Insulated ； Time Bound

NCS 2017 全國計算機會議

2017（2018 / 01 / 01）

940 - 944

繁體中文

密文策略屬性加密是適用於雲端儲存系統的資料存取控制之加密方法。在密文策略屬性加密方法中，資料擁有者利用存取結構及屬性加密資料，並且將嵌有屬性的私鑰發送給使用者，若使用者的屬性能符合密文的存取結構，即可將密文解密。然而，此方法在屬性的撤銷及發放階段，在可信賴第三方及資料擁有者上花費了太多的運算成本。本文提出具選擇性屬性撤銷及有時效之屬性加密協定，此方法將提供具備時效性的使用者屬性私鑰，改良傳統的密文策略屬性加密的缺點，將時戳鑲嵌在密文以及使用者屬性私鑰內，時效到期後便喪失其功能，藉此達到密文以及使用者屬性私鑰管理的便利性。

Ciphertext policy attribute-based encryption, which is also called CPABE, is a cryptography that is suitable for cloud storage system access control. In this protocol, every data user has a secret key with his own attributes and utilizes the access structure and data user's attributes to encrypt data. If the data user's attributes correspond to the data owner's access structure, the data user can decrypt the ciphertext and use this data. However, this protocol's attribute revocation phase and update phase spend too much computation cost. In this article, we proposed an attribute-based encryption scheme with selective attribute revocation and time bound. This scheme provides the data user's attribute secret keys with time bound that the key will be useless when it is out of time. In order to achieve cipher text and convenience of user attribute-based private key management.