Name
Title | ||
|---|---|---|
Sender-Equivocable Encryption Schemes Secure Against Chosen-Ciphertext Attacks Revisited |
Abstract | ||
|---|---|---|
Fehr et al. (2010) proposed the first sender-equivocable encryption scheme secure against chosen-ciphertext attacks (NC-CCA) and proved that NC-CCA security implies security against selective opening chosen-ciphertext attacks (SO-CCA). The NC-CCA security proof of the scheme relies on security against substitution attacks of a new primitive, the "cross-authentication code". However, the security of the cross-authentication code cannot be guaranteed when all the keys used in the code are exposed. Our key observation is that, in the NC-CCA security game, the randomness used in the generation of the challenge ciphertext is exposed to the adversary. Based on this observation, we provide a security analysis of Fehr et al.'s scheme, showing that its NC-CCA security proof is flawed. We also point out that the scheme of Fehr et al. encrypting a single-bit plaintext can be refined to achieve NC-CCA security, free of the cross-authentication code. Furthermore, we propose the notion of "strong cross-authentication code", apply it to Fehr et al.'s scheme, and show that the new version of the latter achieves NC-CCA security for multi-bit plaintexts. |
Year | DOI | Venue |
|---|---|---|
2012 | 10.1515/amcs-2015-0032 | INTERNATIONAL JOURNAL OF APPLIED MATHEMATICS AND COMPUTER SCIENCE |
Keywords | DocType | Volume |
sender-equivocable encryption, chosen-ciphertext attack, cross-authentication code | Journal | 25 |
Issue | ISSN | Citations |
2 | 1641-876X | 5 |
PageRank | References | Authors |
0.41 | 11 | 4 |
Name | Order | Citations | PageRank |
|---|---|---|---|
| zhengan huang | 1 | 241 | 9.82 |
| Shengli Liu | 2 | 484 | 45.70 |
| Baodong Qin | 3 | 190 | 19.40 |
| Kefei Chen | 4 | 1178 | 107.83 |