Department of Computer and Information Security, Sejong University, Seoul, Korea.
PLoS One. 2020 Sep 18;15(9):e0239053. doi: 10.1371/journal.pone.0239053. eCollection 2020.
To deal with dynamically changing user's credentials in identity-based encryption (IBE), providing an efficient key revocation method is a very important issue. Recently, Ma and Lin proposed a generic method of designing a revocable IBE (RIBE) scheme that uses the complete subtree (CS) method by combining IBE and hierarchical IBE (HIBE) schemes. In this paper, we propose a new generic method for designing an RIBE scheme that uses the subset difference (SD) method instead of using the CS method. In order to use the SD method, we generically design an RIBE scheme by combining IBE, identity-based revocation (IBR), and two-level HIBE schemes. If the underlying IBE, IBR, and HIBE schemes are adaptively (or selectively) secure, then our RIBE scheme is also adaptively (or selectively) secure. In addition, we show that the layered SD (LSD) method can be applied to our RIBE scheme and a chosen-ciphertext secure RIBE scheme also can be designed generically.
为了应对基于身份加密（IBE）中用户凭证的动态变化，提供高效的密钥吊销方法是一个非常重要的问题。最近，Ma 和 Lin 提出了一种通用的设计可撤销IBE（RIBE）方案的方法，该方法通过结合IBE 和分层IBE（HIBE）方案使用完全子树（CS）方法。在本文中，我们提出了一种使用子集差（SD）方法而不是 CS 方法设计 RIBE 方案的新通用方法。为了使用 SD 方法，我们通过结合 IBE、基于身份的吊销（IBR）和两级 HIBE 方案来通用地设计 RIBE 方案。如果底层IBE、IBR 和 HIBE 方案是自适应（或选择性）安全的，那么我们的 RIBE 方案也是自适应（或选择性）安全的。此外，我们表明分层 SD（LSD）方法可以应用于我们的 RIBE 方案，并且可以通用地设计选择密文安全的 RIBE 方案。
