scholarly journals Chosen Ciphertext Secure Public Key Threshold Encryption Without Random Oracles

2006 ◽  
pp. 226-243 ◽  
Author(s):  
Dan Boneh ◽  
Xavier Boyen ◽  
Shai Halevi
Keyword(s):  
Public Key ◽  
Random Oracles ◽  
Threshold Encryption

Public-Key Encryption Without Random Oracles

2018 ◽  
pp. 209-214 ◽  
Author(s):  
Fuchun Guo ◽  
Willy Susilo ◽  
Yi Mu
Keyword(s):  
Public Key ◽  
Public Key Encryption ◽  
Random Oracles

Key Replacement Attack on Two Certificateless Signature Schemes without Random Oracles

2010 ◽  
Vol 439-440 ◽  
pp. 1606-1611 ◽  
Author(s):  
Qi Xia ◽  
Chun Xiang Xu ◽  
Yong Yu
Keyword(s):  
Standard Model ◽  
Public Key ◽  
Signature Scheme ◽  
Signature Schemes ◽  
The Public ◽  
Random Oracles ◽  
The Standard Model ◽  
Replacement Attack ◽  
Certificateless Signature

Liu et al. proposed the first certificateless signature scheme without random oracles in 2007. However, Xiong et al. showed that Liu et al.'s scheme is insecure against a malicious-but-passive KGC attack and proposed an improved scheme. In ISA 2009, Yuan et al. also proposed a new certificateless signature scheme without random oracles. Although they claimed that the two schemes are secure in the standard model, this paper shows that both Xiong et al.'s improved scheme and Yuan et al.'s new scheme are vulnerable to key replacement attack, where an adversary, obtaining a signature on a message and replacing the public key of a signer, can forge valid signatures on the same message under the replaced public key. We also give the corresponding modifications of the two schemes to resist key replacement attack.

HIERARCHICAL IDENTITY-BASED PROXY RE-ENCRYPTION WITHOUT RANDOM ORACLES

2010 ◽  
Vol 21 (06) ◽  
pp. 1049-1063 ◽  
Author(s):  
YANLI REN ◽  
DAWU GU ◽  
SHUOZHONG WANG ◽  
XINPENGU ZHANG
Keyword(s):  
Identity Authentication ◽  
Public Key ◽  
Key Generation ◽  
Encryption Scheme ◽  
Number Of Solutions ◽  
Organizational Hierarchy ◽  
Private Key ◽  
Random Oracles ◽  
Identity Based Encryption ◽  
Identity Based

In a proxy re-encryption scheme, a semi-trusted proxy converts a ciphertext for Alice into a ciphertext for Bob without seeing the underlying plaintext. A number of solutions have been proposed in public key settings. Hierarchical identity-based cryptography is a generalization of identity-based encryption that mirrors an organizational hierarchy, which allows a root private key generator to distribute the workload by delegating private key generation and identity authentication to lower-level private key generators. In this paper, we propose a hierarchical identity-based proxy re-encryption (HIBPRE) scheme which achieves IND-PrID-CCA2 security without random oracles. This is the first HIBPRE scheme up to now, and our scheme satisfies unidirectionality, non-interactivity and permits multiple re-encryptions.

Compact public key encryption without full random oracles

2017 ◽  
Vol 41 ◽  
pp. 286-299
Author(s):  
Kazuki Yoneyama ◽  
Goichiro Hanaoka
Keyword(s):  
Public Key ◽  
Public Key Encryption ◽  
Random Oracles
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