scholarly journals Scalable Wildcarded Identity-Based Encryption with Full Security

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1453
Author(s):  
Jiwon Lee ◽  
Seunghwa Lee ◽  
Jihye Kim ◽  
Hyunok Oh
Keyword(s):  
Prime Order ◽  
Experimental Results ◽  
Network Systems ◽  
Practical Applications ◽  
Identity Based Encryption ◽  
Constant Size ◽  
Attribute Based Encryption ◽  
Organization Networks ◽  
Identity Based ◽  
Selective Security

Wildcarded identity-based encryption (WIBE) is an encryption system where one can encrypt messages to multiple users by specifying a pattern, which is a set of identity strings or wildcards. It is a useful primitive for practical applications where users are defined with multiple attributes (or affiliations), such as organization networks or IoT firmware updates. However, the ciphertext size in traditional WIBE schemes are linear to the number of wildcards in the pattern; since the ciphertext size determines the payload in network systems, it degrades the practicality when deployed in transmission-sensitive systems. In this paper, we represent scalable wildcarded identity-based encryption (SWIBE), which achieves a constant-size ciphertext regardless of the number of wildcards (or depth of patterns). the SWIBE scheme also allows the wildcard usage key derivation as well as encryption: a user with wildcarded pattern can delegate keys for the fixed pattern. Compared to the existing WIBE schemes, the SWIBE scheme is the first approach to yield constant-size ciphertext. Moreover, SWIBE also improves encryption time and decryption time while maintaining a key size of 2L, comparable to the key size of L in WIBE schemes (where L is a depth of the pattern). The experimental results show that the decryption time is 3 to 10 times faster than the existing WIBE schemes, and 650 times faster than the attribute-based encryption with constant-size ciphertext. For the security, we first propose the selective-CPA-secure SWIBE scheme in a prime order bilinear group and extend it to be selective-CCA-secure. Then we also propose a fully-secure SWIBE scheme which can overcome the selective security.

Cryptanalysis of a Compact Anonymous HIBE with Constant Size Private Keys

2018 ◽  
Vol 62 (8) ◽  
pp. 1087-1091
Author(s):  
Xi-Jun Lin ◽  
Lin Sun ◽  
Haipeng Qu ◽  
He-Qun Xian
Keyword(s):  
Standard Model ◽  
Prime Order ◽  
Private Key ◽  
Identity Based Encryption ◽  
Constant Size ◽  
The Standard Model ◽  
Identity Based

AbstractRecently, Zhang et al. proposed a new anonymous hierarchical identity-based encryption (anonymous HIBE) over prime order groups to achieve both constant size private key and constant size ciphertext. Moreover, a double exponent technique was used to provide anonymity. They proved that their scheme is secure and anonymous against chosen plaintext attacks in the standard model. In this paper, we point out that their scheme is insecure.

Black-Box Accountable Authority Identity-Based Revocation System

2019 ◽  
Vol 63 (4) ◽  
pp. 525-535
Author(s):  
Zhen Zhao ◽  
Ge Wu ◽  
Fuchun Guo ◽  
Willy Susilo ◽  
Yi Mu ◽  
...  
Keyword(s):  
Random Oracle ◽  
Black Box ◽  
Key Escrow ◽  
Full Black ◽  
Practical Applications ◽  
Private Key ◽  
Constant Size ◽  
Full Control ◽  
Security Models ◽  
Identity Based

Abstract Identity-based revocation system (IBRS) generates the ciphertext with a revoked identity list such that only the non-revoked identities can use their private keys to decrypt this ciphertext. IBRS can be efficiently applied in some practical applications, such as the pay-TV systems when the number of revoked identities are much less than the non-revoked ones. However, since IBRS is based on identity-based cryptography, it also suffers from the inherent key escrow problem where the private key generator (PKG) has full control of each user’s private key. As a consequence, it is hard to judge whether a pirated private key is generated by the PKG or the suspected user. There is no study on IBRS fulfilling accountability in literature to date. In this paper, we introduce the notion of accountable authority IBRS (A-IBRS), which provides accountability in IBRS schemes. In an A-IBRS, the aforementioned problem can be alleviated and resolved. Furthermore, a full black-box A-IBRS can distinguish the creator of a black box between the PKG and the associated user and the dishonest PKG is allowed to access the decryption results of the user private key. We formalize the definition and security models of the full black-box A-IBRS schemes. Then, we present a concrete full black-box A-IBRS scheme with constant-size master public key and private key. Finally, we prove the security of our scheme under the defined security models without random oracle.

scholarly journals Hierarchical Identity-Based Encryption with Constant-Size Private Keys

ETRI Journal ◽  
2012 ◽  
Vol 34 (1) ◽  
pp. 142-145 ◽  
Author(s):  
Leyou Zhang ◽  
Qing Wu ◽  
Yupu Hu
Keyword(s):  
Identity Based Encryption ◽  
Constant Size ◽  
Identity Based

scholarly journals A New User Revocable Ciphertext-Policy Attribute-Based Encryption with Ciphertext Update

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zhe Liu ◽  
Fuqun Wang ◽  
Kefei Chen ◽  
Fei Tang
Keyword(s):  
Secret Key ◽  
Data Confidentiality ◽  
Encrypted Data ◽  
Diffie Hellman ◽  
Security Proof ◽  
Attribute Based Encryption ◽  
Challenge Ciphertext ◽  
Identity Based ◽  
Ciphertext Policy ◽  
Selective Security

The revocable ciphertext-policy attribute-based encryption (R-CP-ABE) is an extension of ciphertext-policy attribute-based encryption (CP-ABE), which can realize user direct revocation and maintain a short revocation list. However, the revoked users can still decrypt the previously authorized encrypted data with their old key. The R-CP-ABE scheme should provide a mechanism to protect the encrypted data confidentiality by disqualifying the revoked users from accessing the previously encrypted data. Motivated by practical needs, we propose a new user R-CP-ABE scheme that simultaneously supports user direct revocation, short revocation list, and ciphertext update by incorporating the identity-based and time-based revocable technique. The scheme provides a strongly selective security proof under the modified decisional q -parallel bilinear Diffie–Hellman Exponent problem, where “strongly” means that the adversary can query the secret key of a user whose attribute set satisfies the challenge ciphertext access structure and whose identity is in the revocation list.

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