Secure Key Storage and Access Delegation Through Cloud Storage

2020 ◽  
Vol 11 (4) ◽  
pp. 45-64
Author(s):  
Bharati Mishra ◽  
Debasish Jena ◽  
Ramasubbareddy Somula ◽  
S. Sankar
Keyword(s):  
Key Management ◽  
Cloud Storage ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Key Generation ◽  
Encryption Scheme ◽  
Lightweight Cryptography ◽  
Encryption Schemes ◽  
Client Side ◽  
Cloud User

Cloud storage is gaining popularity to store and share files. To secure the files, cloud storage providers supply client interfaces with the facility to encrypt the files and upload them into the cloud. When client-side encryption is done, the onus of key management lies with the cloud user. Public key proxy re-encryption mechanisms can be used to distribute the key among stakeholders of the file. However, clients use low powered devices like mobile phones to share their files. Lightweight cryptography operations are needed to carry out the encryption operations. Ring-LWE-based encryption scheme meets this criterion. In this work, a proxy re-encryption scheme is proposed to distribute the file key. The scheme is proved CCA secure under Ring-LWE assumption in the random oracle model. The performance of the scheme is compared with the existing proxy re-encryption schemes which are observed to show better performance for re-encryption and re-key generation.

scholarly journals A multi-authority approach to various predicate encryption types

2019 ◽  
Vol 88 (2) ◽  
pp. 363-390
Author(s):  
Tim van de Kamp ◽  
Andreas Peter ◽  
Willem Jonker
Keyword(s):  
Admissible Pair ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Encryption Scheme ◽  
Encoding Scheme ◽  
Decentralized System ◽  
Conversion Algorithm ◽  
Encryption Schemes ◽  
Generic Construction ◽  
Predicate Encryption

Abstract We propose a generic construction for fully secure decentralized multiauthority predicate encryption. In such multiauthority predicate encryption scheme, ciphertexts are associated with one or more predicates from various authorities and only if a user has a set of decryption keys that evaluates all predicates to true, the user is able to recover the message. In our decentralized system, anyone can create a new authority and issue decryption keys for their own predicates. We introduce the concept of a multi-authority admissible pair encoding scheme and, based on these encodings, we give a generic conversion algorithm that allows us to easily combine various predicate encryption schemes into a multi-authority predicate encryption variant. The resulting encryption schemes are proven fully secure under standard subgroup decision assumptions in the random oracle model. Finally, by instantiating several concrete multi-authority admissible pair encoding schemes and applying our conversion algorithm, we are able to create a variety of novel multi-authority predicate encryption schemes.

scholarly journals An Efficient Chaotic Map-Based Authentication Scheme with Mutual Anonymity

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Yousheng Zhou ◽  
Junfeng Zhou ◽  
Feng Wang ◽  
Feng Guo
Keyword(s):  
Key Management ◽  
Chaotic Map ◽  
Mutual Authentication ◽  
Security Analysis ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Authentication Scheme ◽  
Session Key ◽  
The Real ◽  
Shared Key

A chaotic map-based mutual authentication scheme with strong anonymity is proposed in this paper, in which the real identity of the user is encrypted with a shared key between the user and the trusted server. Only the trusted server can determine the real identity of a user during the authentication, and any other entities including other users of the system get nothing about the user’s real identity. In addition, the shared key of encryption can be easily computed by the user and trusted server using the Chebyshev map without additional burdensome key management. Once the partnered two users are authenticated by the trusted server, they can easily proceed with the agreement of the session key. Formal security analysis demonstrates that the proposed scheme is secure under the random oracle model.

scholarly journals Speech Encryption Scheme Based on Ciphertext Policy Hierarchical Attribute in Cloud Storage

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qiuyu Zhang ◽  
Zhenyu Zhao ◽  
Minrui Fu
Keyword(s):  
Access Control ◽  
Cloud Storage ◽  
Random Oracle Model ◽  
Access Structure ◽  
Encryption Scheme ◽  
Hierarchical Processing ◽  
Fine Grained ◽  
Speech Data ◽  
Speech Encryption ◽  
Ciphertext Policy

In order to ensure the confidentiality and secure sharing of speech data, and to solve the problems of slow deployment of attribute encryption systems and fine-grained access control in cloud storage, a speech encryption scheme based on ciphertext policy hierarchical attributes was proposed. First, perform hierarchical processing of the attributes of the speech data to reflect the hierarchical structure and integrate the hierarchical access structure into a single-access structure. Second, use the attribute fast encryption framework to construct the attribute encryption scheme of the speech data, and use the integrated access to the speech data; thus, the structure is encrypted and uploaded to the cloud for storage and sharing. Finally, use the hardness of decisional bilinear Diffie–Hellman (DBDH) assumption to prove that the proposed scheme is secure in the random oracle model. The theoretical security analysis and experimental results show that the proposed scheme can achieve efficient and fine-grained access control and is secure and extensible.

scholarly journals Security of signature schemes in the presence of key-dependent messages

2010 ◽  
Vol 47 (1) ◽  
pp. 15-29
Author(s):  
Madeline González Muñiz ◽  
Rainer Steinwndt
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Signature Scheme ◽  
Forward Security ◽  
Signature Schemes ◽  
Encryption Schemes ◽  
Time Signature ◽  
Made In

Abstract In recent years, quite some progress has been made in understand- ing the security of encryption schemes in the presence of key-dependent plaintexts. Here, we motivate and explore the security of a setting, where an adversary against a signature scheme can access signatures on key-dependent messages. We propose a way to formalize the security of signature schemes in the pres- ence of key-dependent signatures (KDS). It turns out that the situation is quite different from key-dependent encryption: already to achieve KDS-security under non-adaptive chosen message attacks, the use of a stateful signing algorithm is inevitable-even in the random oracle model. After discussing the connection be- tween key-dependent signing and forward security, we present a compiler to lift any EUF-CMA secure one-time signature scheme to a forward secure signature scheme offering KDS-CMA security.

scholarly journals Efficient Certificateless Anonymous Multi-Receiver Encryption Scheme without Bilinear Parings

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Ronghai Gao ◽  
Jiwen Zeng ◽  
Lunzhi Deng
Keyword(s):  
Mobile Devices ◽  
Security Analysis ◽  
Mobile Network ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Bilinear Pairing ◽  
Internet Technology ◽  
Security And Privacy ◽  
Encryption Scheme ◽  
The Troubles

With the growing development of Internet technology and popularization of mobile devices, we easily access the Internet anytime and anywhere by mobile devices. It has brought great convenience for our lives. But it brought more challenges than traditional wired communication, such as confidentiality and privacy. In order to improve security and privacy protection in using mobile network, numerous multi-receiver identity-based encryption schemes have been proposed with bilinear pairing and probabilistic hap-to-point (HTP) function. To address the troubles of private key escrow in multi-receiver encryption scheme based on ID-PKC, recently, some certificateless anonymous multi-receiver encryption (CLAMRE) schemes are introduced. But previous CLAMRE schemes using the bilinear pairing are not suitable to mobile device because the use of bilinear pairing and probabilistic hash-to-point (HTP) function results in expensive operation costs in encryption or decryption. In this paper, we propose an efficient CLAMRE scheme using elliptic curve cryptography (ECC) without bilinear pairing and HTP hash function. Since our scheme does not use bilinear pairing and HTP operation during the encryption and decryption process, the proposed CLAMRE scheme has much less computation cost than the latest CLAMRE schemes. Performance analysis shows that runtime of our scheme is much less when the sender generates ciphertext, compared with existing schemes. Security analysis shows proposed CLAMRE scheme provides confidentiality of message and receiver anonymity under the random oracle model with the difficulties of decision Diffie-Hellman problem and against the adversaries defined in CL-PKC system.

scholarly journals Compiled Constructions towards Post-Quantum Group Key Exchange: A Design from Kyber

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1853
Author(s):  
José Ignacio Escribano Pablos ◽  
María Isabel González Vasco ◽  
Misael Enrique Marriaga ◽  
Ángel Luis Pérez del Pozo
Keyword(s):  
Random Oracle Model ◽  
Building Blocks ◽  
Random Oracle ◽  
Key Exchange ◽  
Encryption Scheme ◽  
Secret Key ◽  
Key Exchange Protocol ◽  
Group Key ◽  
Group Key Exchange ◽  
Starting Point

A group authenticated key exchange (GAKE) protocol allows a set of parties belonging to a certain designated group to agree upon a common secret key through an insecure communication network. In the last few years, many new cryptographic tools have been specifically designed to thwart attacks from adversaries which may have access to (different kinds of) quantum computation resources. However, few constructions for group key exchange have been put forward. Here, we propose a four-round GAKE which can be proven secure under widely accepted assumptions in the Quantum Random Oracle Model. Specifically, we integrate several primitives from the so-called Kyber suite of post-quantum tools in a (slightly modified) compiler from Abdalla et al. (TCC 2007). More precisely, taking as a starting point an IND-CPA encryption scheme from the Kyber portfolio, we derive, using results from Hövelmanns et al. (PKC 2020), a two-party key exchange protocol and an IND-CCA encryption scheme and prove them fit as building blocks for our compiled construction. The resulting GAKE protocol is secure under the Module-LWE assumption, and furthermore achieves authentication without the use of (expensive) post-quantum signatures.

scholarly journals Hierarchical authority based weighted attribute encryption scheme

2019 ◽  
Vol 16 (3) ◽  
pp. 797-813
Author(s):  
Qiuting Tian ◽  
Dezhi Han ◽  
Yanmei Jiang
Keyword(s):  
Data Storage ◽  
Cloud Storage ◽  
Encryption Scheme ◽  
Storage Security ◽  
Fine Grained ◽  
Security Proof ◽  
Attribute Based Encryption ◽  
Encryption Schemes ◽  
And Performance ◽  
Cloud Storage Environment

With the development of cloud storage technology, data storage security has become increasingly serious. Aiming at the problem that existing attribute-based encryption schemes do not consider hierarchical authorities and the weight of attribute. A hierarchical authority based weighted attribute encryption scheme is proposed. This scheme will introduce hierarchical authorities and the weight of attribute into the encryption scheme, so that the authorities have a hierarchical relationship and different attributes have different importance. At the same time, the introduction of the concept of weight makes this scheme more flexible in the cloud storage environment and enables fine-grained access control. In addition, this scheme implements an online/offline encryption mechanism to improve the security of stored data. Security proof and performance analysis show that the scheme is safe and effective, and it can resist collusion attacks by many malicious users and authorization centers. It is more suitable for cloud storage environments than other schemes.

A Cloud Storage Encryption Scheme Based on Separated Key and Encryption Policy

2014 ◽  
Vol 989-994 ◽  
pp. 2543-2546
Author(s):  
Peng Wang ◽  
Fu Zheng Zhang ◽  
Chun Lei Han
Keyword(s):  
Data Storage ◽  
Key Management ◽  
Cloud Storage ◽  
High Performance ◽  
Low Cost ◽  
Data Encryption ◽  
Encryption Scheme ◽  
Security Issues ◽  
Secure Storage ◽  
Storage Encryption

With the continuous expansion of the scale data storage, cloud storage technology for its high performance and low cost to get a lot of attention and support. However, the security issues of cloud storage data hinder its further promotion. For the current cloud storage applications of data stored encrypted, a cloud storage encryption scheme based on the separated key and encryption policy is proposed. By strengthening the data encryption key management and data encryption algorithm, the system achieves a more secure storage of data assurance in the technical level.

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