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.

Fully Secure Ciphertext-Policy Attribute-Based Encryption in Prime Order Group

2012 ◽  
Vol 263-266 ◽  
pp. 2920-2923
Author(s):  
Song Feng Lu ◽  
Yu Zhang ◽  
Jie Sun ◽  
Liping Yang
Keyword(s):  
Prime Order ◽  
Encryption Scheme ◽  
Secret Key ◽  
Order Group ◽  
Security Proof ◽  
Attribute Based Encryption ◽  
Ciphertext Policy

We present a fully secure ciphertext-policy attribute-based encryption (CP-ABE) scheme in prime order group by using a tool which can convert composite order paring-based encryption scheme into prime order one. Although, a fully secure CP-ABE scheme in prime order group has been proposed recently, our scheme needs less master secret key size and can be seen as a different version of it. Besides, the sketch of our scheme's security proof is also given.

scholarly journals Ciphertext-policy attribute-based encryption with hidden sensitive policy from keyword search techniques in smart city

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Fei Meng ◽  
Leixiao Cheng ◽  
Mingqiang Wang
Keyword(s):  
Smart City ◽  
Keyword Search ◽  
Sensitive Information ◽  
Security Model ◽  
Computational Overhead ◽  
Diffie Hellman ◽  
Attribute Based Encryption ◽  
Iot Devices ◽  
Ciphertext Policy ◽  
Access Policies

AbstractCountless data generated in Smart city may contain private and sensitive information and should be protected from unauthorized users. The data can be encrypted by Attribute-based encryption (CP-ABE), which allows encrypter to specify access policies in the ciphertext. But, traditional CP-ABE schemes are limited because of two shortages: the access policy is public i.e., privacy exposed; the decryption time is linear with the complexity of policy, i.e., huge computational overheads. In this work, we introduce a novel method to protect the privacy of CP-ABE scheme by keyword search (KS) techniques. In detail, we define a new security model called chosen sensitive policy security: two access policies embedded in the ciphertext, one is public and the other is sensitive and hidden. If user's attributes don't satisfy the public policy, he/she cannot get any information (attribute name and its values) of the hidden one. Previous CP-ABE schemes with hidden policy only work on the “AND-gate” access structure or their ciphertext size or decryption time maybe super-polynomial. Our scheme is more expressive and compact. Since, IoT devices spread all over the smart city, so the computational overhead of encryption and decryption can be shifted to third parties. Therefore, our scheme is more applicable to resource-constrained users. We prove our scheme to be selective secure under the decisional bilinear Diffie-Hellman (DBDH) assumption.

An Attribute-Based Searchable Encryption Scheme for Non-Monotonic Access Structure

2020 ◽  
pp. 263-283 ◽  
Author(s):  
Mamta ­ ◽  
Brij B. Gupta
Keyword(s):  
Access Control ◽  
Searchable Encryption ◽  
Access Structure ◽  
Encryption Scheme ◽  
Security Model ◽  
Secret Key ◽  
Fine Grained ◽  
Diffie Hellman ◽  
Attribute Based Encryption ◽  
Encryption Schemes

Attribute based encryption (ABE) is a widely used technique with tremendous application in cloud computing because it provides fine-grained access control capability. Owing to this property, it is emerging as a popular technique in the area of searchable encryption where the fine-grained access control is used to determine the search capabilities of a user. But, in the searchable encryption schemes developed using ABE it is assumed that the access structure is monotonic which contains AND, OR and threshold gates. Many ABE schemes have been developed for non-monotonic access structure which supports NOT gate, but this is the first attempt to develop a searchable encryption scheme for the same. The proposed scheme results in fast search and generates secret key and search token of constant size and also the ciphertext components are quite fewer than the number of attributes involved. The proposed scheme is proven secure against chosen keyword attack (CKA) in selective security model under Decisional Bilinear Diffie-Hellman (DBDH) assumption.

scholarly journals A Lightweight Fine-Grained Search Scheme over Encrypted Data in Cloud-Assisted Wireless Body Area Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Mingsheng Cao ◽  
Luhan Wang ◽  
Zhiguang Qin ◽  
Chunwei Lou
Keyword(s):  
Keyword Search ◽  
Body Area Networks ◽  
Wireless Body Area Networks ◽  
Security And Privacy ◽  
Body Area ◽  
Encrypted Data ◽  
Fine Grained ◽  
Resource Limited ◽  
Attribute Based Encryption ◽  
Ciphertext Policy

The wireless body area networks (WBANs) have emerged as a highly promising technology that allows patients’ demographics to be collected by tiny wearable and implantable sensors. These data can be used to analyze and diagnose to improve the healthcare quality of patients. However, security and privacy preserving of the collected data is a major challenge on resource-limited WBANs devices and the urgent need for fine-grained search and lightweight access. To resolve these issues, in this paper, we propose a lightweight fine-grained search over encrypted data in WBANs by employing ciphertext policy attribute based encryption and searchable encryption technologies, of which the proposed scheme can provide resource-constraint end users with fine-grained keyword search and lightweight access simultaneously. We also formally define its security and prove that it is secure against both chosen plaintext attack and chosen keyword attack. Finally, we make a performance evaluation to demonstrate that our scheme is much more efficient and practical than the other related schemes, which makes the scheme more suitable for the real-world applications.

scholarly journals Identity-Based Key Exchange on In-Vehicle Networks: CAN-FD & FlexRay

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4919
Author(s):  
Bogdan Groza ◽  
Pal-Stefan Murvay
Keyword(s):  
Bilinear Pairings ◽  
Group Extension ◽  
Key Exchange ◽  
Area Network ◽  
Secret Key ◽  
Cryptographic Primitives ◽  
Diffie Hellman ◽  
Vehicle Networks ◽  
Identity Based ◽  
Diffie Hellman Key Exchange

Security has become critical for in-vehicle networks as they carry safety-critical data from various components, e.g., sensors or actuators, and current research proposals were quick to react with cryptographic protocols designed for in-vehicle buses, e.g., CAN (Controller Area Network). Obviously, the majority of existing proposals are built on cryptographic primitives that rely on a secret shared key. However, how to share such a secret key is less obvious due to numerous practical constraints. In this work, we explore in a comparative manner several approaches based on a group extension of the Diffie–Hellman key-exchange protocol and identity-based authenticated key agreements. We discuss approaches based on conventional signatures and identity-based signatures, garnering advantages from bilinear pairings that open road to several well-known cryptographic constructions: short signatures, the tripartite Diffie–Hellman key exchange and identity-based signatures or key exchanges. Pairing-based cryptographic primitives do not come computationally cheap, but they offer more flexibility that leads to constructive advantages. To further improve on performance, we also account for pairing-free identity-based key exchange protocols that do not require expensive pairing operations nor explicit signing of the key material. We present both computational results on automotive-grade controllers as well as bandwidth simulations with industry-standard tools, i.e., CANoe, on modern in-vehicle buses CAN-FD and FlexRay.

scholarly journals Light Weight Cryptography based Medical Data and Image Encryption Scheme

Webology ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 88-104
Author(s):  
M. Raja ◽  
Dr.S. Dhanasekaran ◽  
Dr.V. Vasudevan
Keyword(s):  
Data Privacy ◽  
Medical Information ◽  
Security Analysis ◽  
Encrypted Data ◽  
Attribute Based Encryption ◽  
Identity Based ◽  
Information Confidentiality ◽  
Processing And Storage ◽  
And Storage ◽  
Maintenance Problem

Many medical companies use cloud technology to collect, distribute and transmit medical records. Given the need for medical information, confidentiality is a key issue. In this study, we propose an encrypted scheme based on encrypted data for an electronic healthcare environment. We use hybrid Attribute based encryption and Triple DES encryption technique (ABETDES) scheme, including identity-based cryptography (IBC), to ensure data privacy through communication channels և to improve the reliability of cloud computing. There are also limited indicators of light processing and storage resources. This solves a serious maintenance problem and ensures that a private key is created where it is not blind. The introduction of a security option, a comprehensive security analysis to protect ciphertext, shows that our program is effective against many known attacks and compared to existing methods.

scholarly journals Server-Aided Revocable Attribute-Based Encryption from Lattices

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xingting Dong ◽  
Yanhua Zhang ◽  
Baocang Wang ◽  
Jiangshan Chen
Keyword(s):  
Access Control ◽  
Standard Model ◽  
Secret Key ◽  
Bilinear Maps ◽  
Encrypted Data ◽  
Fine Grained ◽  
Attribute Based Encryption ◽  
The Standard Model ◽  
Learning With Errors

Attribute-based encryption (ABE) can support a fine-grained access control to encrypted data. When the user’s secret-key is compromised, the ABE system has to revoke its decryption privileges to prevent the leakage of encrypted data. Although there are many constructions about revocable ABE from bilinear maps, the situation with lattice-based constructions is less satisfactory, and a few efforts were made to close this gap. In this work, we propose the first lattice-based server-aided revocable attribute-based encryption (SR-ABE) scheme and thus the first such construction that is believed to be quantum resistant. In the standard model, our scheme is proved to be secure based on the hardness of the Learning With Errors (LWE) problem.

scholarly journals Efficient Ciphertext-Policy Attribute-Based Online/Offline Encryption with User Revocation

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Haiying Ma ◽  
Zhanjun Wang ◽  
Zhijin Guan
Keyword(s):  
Mobile Devices ◽  
Computational Costs ◽  
Private Key ◽  
Attribute Based Encryption ◽  
User Revocation ◽  
Key Update ◽  
Subset Difference ◽  
Ciphertext Policy ◽  
Selective Security ◽  
Over Time

Attribute-Based Encryption (ABE) must provide an efficient revocation mechanism since a user’s private key can be compromised or expired over time. The existing revocable ABE schemes have the drawbacks of heavy computational costs on key updates and encryption operations, which make the entities for performing these operations a possible bottleneck in practice applications. In this paper, we propose an efficient Ciphertext-Policy Attribute-Based Online/Offline Encryption with user Revocation (R-CP-ABOOE). We integrate the subset difference method with ciphertext-policy ABE to significantly improve key-update efficiency on the side of the trusted party from O(rlog⁡(N/r)) to O(r), where N is the number of users and r is the number of revoked users. To reduce the encryption burden for mobile devices, we use the online/offline technology to shift the majority of encryption work to the offline phase, and then mobile devices only need to execute a few simple computations to create a ciphertext. In addition, we exploit a novel trick to prove its selective security under the q-type assumption. Performance analysis shows that our scheme greatly improves the key-update efficiency for the trusted party and the encryption efficiency for mobile devices.

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