Some Remarks on Cocks'Identity-Based Encryption Scheme

The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However,a notable drawback of Cocks’scheme is the significant expansion of the ciphertext,and some of its limitations have been addressed in subsequent research.Recently,Cotan and Teşeleanu highlighted that previous studies on Cocks’scheme relied on a trial-and-error method based on Jacobi symbols to generate the necessary parameters for the encryption process.They enhanced the encryption speed of Cocks’scheme by eliminating this trialand-error method.Based on security analysis,this study concludes that the security of Cotan-Teşeleanu’s proposal cannot be directly derived from the security of the original Cocks’scheme.Furthermore,by adopting the Cotan-Teşeleanu method and introducing an additional variable as a public element,this study develops a similar enhancement scheme that not only accelerates the encryption speed but also provides security equivalent to the original Cocks’scheme.

Construction and Implementation of a Privacy-Preserving Identity-Based Encryption Architecture

A recent proposal by Adams integrates the digital credentials (DC) technology of Brands with the identity-based encryption (IBE) technology of Boneh and Franklin to create an IBE scheme that demonstrably enhances privacy for users. We refer to this scheme as a privacy-preserving identity-based encryption (PP-IBE) construction. In this paper, we discuss the concrete implementation considerations for PP-IBE and provide a detailed instantiation (based on q-torsion groups in supersingular elliptic curves) that may be useful both for proof-of-concept purposes and for pedagogical purposes.

OBLIVIOUS TRANSFER WITH ACCESS CONTROL AND IDENTITY-BASED ENCRYPTION WITH ANONYMOUS KEY ISSUING

In ACM'CCS 2009,Camenisch,et al.proposed the Oblivious Transfer with Access Control(AC-OT) in which each item is associated with an attribute set and can only be available,on request,to the users who have all the attributes in the associated set.Namely,AC-OT achieves access control policy for conjunction of attributes.Essentially,the functionality of AC-OT is equivalent to the sim-plified version that we call AC-OT-SV:for each item,one attribute is associated with it,and it is requested that only the users who possess the associated attribute can obtain the item by queries.On one hand,AC-OT-SV is a special case of AC-OT when there is just one associated attribute with each item.On the other hand,any AC-OT can be realized by an AC-OT-SV.In this paper,we first present a concrete AC-OT-SV protocol which is proved to be secure in the model defined by Camenisch,et al..Then from the protocol,interestingly,a concrete Identity-Based Encryption(IBE) with Anonymous Key Issuing(AKI) is given which is just a direct application to AC-OT-SV.By comparison,we show that the AKI protocol we present is more efficient in communications than that proposed by Chow.

Security Analysis of a Privacy-Preserving Identity-Based Encryption Architecture

Identity-Based Encryption (IBE) has seen limited adoption, largely due to the absolute trust that must be placed in the private key generator (PKG)—an authority that computes the private keys for all the users in the environment. Several constructions have been proposed to reduce the trust required in the PKG (and thus preserve the privacy of users), but these have generally relied on unrealistic assumptions regarding non-collusion between various entities in the system. Unfortunately, these constructions have not significantly improved IBE adoption rates in real-world environments. In this paper, we present a construction that reduces trust in the PKG without unrealistic non-collusion assumptions. We achieve this by incorporating a novel combination of digital credential technology and bilinear maps, and making use of multiple randomly-chosen entities to complete certain tasks. The main result and primary contribution of this paper are a thorough security analysis of this proposed construction, examining the various entity types, attacker models, and collusion opportunities in this environment. We show that this construction can prevent, or at least mitigate, all considered attacks. We conclude that our construction appears to be effective in preserving user privacy and we hope that this construction and its security analysis will encourage greater use of IBE in real-world environments.

Identity-Based Encryption with Keyword Search from Lattice Assumption

Public key encryption scheme with keyword search （PEKS） enables us to search the encrypted data in a cloud server with a keyword, and no one can obtain any infor- mation about the encrypted data without the trapdoor corresponding to the keyword. The PEKS is useful to keep the management of large data storages secure such as those in a cloud. In this paper, to protect against quantum computer attacks, we present a lattice-based identity-based encryption scheme with key- word search. We have proved that our scheme can achieve ciphertext indistinguishability in the random oracle model, and our scheme can also achieve trapdoor security. In particular, our scheme can designate a unique tester to test and return the search results, therefore it does not need a secure channel. To the best of our knowledge, our scheme is the first iden- tity-based encryption scheme with keyword search from lattice assumption.

Verifiable Identity-Based Encryption with Keyword Search for IoT from Lattice

Internet of Things(IoT),which provides the solution of connecting things and devices,has increasingly developed as vital tools to realize intelligent life.Generally,source-limited IoT sensors outsource their data to the cloud,which arises the concerns that the transmission of IoT data is happening without appropriate consideration of the profound security challenges involved.Though encryption technology can guarantee the confidentiality of private data,it hinders the usability of data.Searchable encryption(SE)has been proposed to achieve secure data sharing and searching.However,most of existing SE schemes are designed under conventional hardness assumptions and may be vulnerable to the adversary with quantum computers.Moreover,the untrusted cloud server may perform an unfaithful search execution.To address these problems,in this paper,we propose the first verifiable identity-based keyword search(VIBKS)scheme from lattice.In particular,a lattice-based delegation algorithm is adopted to help the data user to verify both the correctness and the integrity of the search results.Besides,in order to reduce the communication overhead,we refer to the identity-based mechanism.We conduct rigorous proof to demonstrate that the proposed VIBKS scheme is ciphertext indistinguishable secure against the semi-honestbut-curious adversary.In addition,we give the detailed computation and communication complexity of our VIBKS and conduct a series of experiments to validate its efficiency performance.

Hybrid Cloud Security by Revocable KUNodes-Storage with Identity-Based Encryption

Cloud storage is a service involving cloud service providers providingstorage space to customers. Cloud storage services have numerous advantages,including convenience, high computation, and capacity, thereby attracting usersto outsource data in the cloud. However, users outsource data directly via cloudstage services that are unsafe when outsourcing data is sensitive for users. Therefore, cipher text-policy attribute-based encryption is a promising cryptographicsolution in a cloud environment, and can be drawn up for access control by dataowners (DO) to define access policy. Unfortunately, an outsourced architectureapplied with attribute-based encryption introduces numerous challenges, including revocation. This issue is a threat to the data security of DO. Furthermore,highly secure and flexible cipher text-based attribute access control with role hierarchy user grouping in cloud storage is implemented by extending the KUNodes(revocation) storage identity-based encryption. Result is evaluated using Cloudsim, and our algorithm outperforms in terms of computational cost by consuming32 MB for 150-MB files.

Identity-based encryption with wildcards in the standard model

In this article, based on Chatterjee-Sarkar＇ hierarchical identity-based encryption （HIBE）, a novel identity-based encryption with wildcards （WIBE） scheme is proposed and is proven secure in the standard model （without random oracle）. The proposed scheme is proven to be secure assuming that the decisional Bilinear Diffie-Hellman （DBDH） problem is hard. Compared with the Wa-WIBE scheme that is secure in the standard model, our scheme has shorter common parameters and ciphertext length.

Identity-based Encryption with Non-Interactive Opening

An identity-based encryption(IBE) was studied with non-interactively opening property that the plain text of a ciphertext can be revealed without affecting the security of the encryption system.Two kinds of non-interactive opening properties for IBE schemes were defined along with a concrete scheme in each case.

Reflections on the security proofs of Boneh-Franklin identity-based encryption scheme

In this paper, we first review the existing proofs of the Boneh-Franklin identity-based encryption scheme (BF-IBE for short), and show how to admit a new proof by slightly modifying the specifications of the hash functions of the original BF-IBE. Compared with prior proofs, our new proof provides a tighter security reduction and minimizes the use of random oracles, thus indicates BF-IBE has better provable security with our new choices of hash functions. The techniques developed in our proof can also be applied to improving security analysis of some other IBE schemes. As an independent technical contribution, we also give a rigorous proof of the Fujisaki-Okamoto (FO) transformation in the case of CPA-to-CCA, which demonstrates the efficiency of the FO-transformation (CPA-to-CCA), in terms of the tightness of security reduction, has long been underestimated. This result can remarkably benefit the security proofs of encryption schemes using the FO-transformation for CPA-to-CCA enhancement.

Physical Layer Encryption of OFDM-PON Based on Quantum Noise Stream Cipher with Polar Code

Orthogonal frequency division multiplexing passive optical network(OFDM-PON) has superior anti-dispersion property to operate in the C-band of fiber for increased optical power budget. However,the downlink broadcast exposes the physical layer vulnerable to the threat of illegal eavesdropping. Quantum noise stream cipher(QNSC) is a classic physical layer encryption method and well compatible with the OFDM-PON. Meanwhile, it is indispensable to exploit forward error correction(FEC) to control errors in data transmission. However, when QNSC and FEC are jointly coded, the redundant information becomes heavier and thus the code rate of the transmitted signal will be largely reduced. In this work, we propose a physical layer encryption scheme based on polar-code-assisted QNSC. In order to improve the code rate and security of the transmitted signal, we exploit chaotic sequences to yield the redundant bits and utilize the redundant information of the polar code to generate the higher-order encrypted signal in the QNSC scheme with the operation of the interleaver.We experimentally demonstrate the encrypted 16/64-QAM, 16/256-QAM, 16/1024-QAM, 16/4096-QAM QNSC signals transmitted over 30-km standard single mode fiber. For the transmitted 16/4096-QAM QNSC signal, compared with the conventional QNSC method, the proposed method increases the code rate from 0.1 to 0.32 with enhanced security.

Enhancing IoT Data Security with Lightweight Blockchain and Okamoto Uchiyama Homomorphic Encryption

Blockchain technology has garnered significant attention from global organizations and researchers due to its potential as a solution for centralized system challenges.Concurrently,the Internet of Things(IoT)has revolutionized the Fourth Industrial Revolution by enabling interconnected devices to offer innovative services,ultimately enhancing human lives.This paper presents a new approach utilizing lightweight blockchain technology,effectively reducing the computational burden typically associated with conventional blockchain systems.By integrating this lightweight blockchain with IoT systems,substantial reductions in implementation time and computational complexity can be achieved.Moreover,the paper proposes the utilization of the Okamoto Uchiyama encryption algorithm,renowned for its homomorphic characteristics,to reinforce the privacy and security of IoT-generated data.The integration of homomorphic encryption and blockchain technology establishes a secure and decentralized platformfor storing and analyzing sensitive data of the supply chain data.This platformfacilitates the development of some business models and empowers decentralized applications to perform computations on encrypted data while maintaining data privacy.The results validate the robust security of the proposed system,comparable to standard blockchain implementations,leveraging the distinctive homomorphic attributes of the Okamoto Uchiyama algorithm and the lightweight blockchain paradigm.

A Blockchain-Based Proxy Re-Encryption Scheme with Conditional Privacy Protection and Auditability

With the development of Internet of Things technology,intelligent door lock devices are widely used in the field of house leasing.In the traditional housing leasing scenario,problems of door lock information disclosure,tenant privacy disclosure and rental contract disputes frequently occur,and the security,fairness and auditability of the housing leasing transaction cannot be guaranteed.To solve the above problems,a blockchain-based proxy re-encryption scheme with conditional privacy protection and auditability is proposed.The scheme implements fine-grained access control of door lock data based on attribute encryption technology with policy hiding,and uses proxy re-encryption technology to achieve auditable supervision of door lock information transactions.Homomorphic encryption technology and zero-knowledge proof technology are introduced to ensure the confidentiality of housing rent information and the fairness of rent payment.To construct a decentralized housing lease transaction architecture,the scheme realizes the efficient collaboration between the door lock data ciphertext stored under the chain and the key information ciphertext on the chain based on the blockchain and InterPlanetary File System.Finally,the security proof and computing performance analysis of the proposed scheme are carried out.The results show that the scheme can resist the chosen plaintext attack and has low computational cost.

Practical continuous leakage-resilient CCA secure identity-based encryption

Leakage of private information including private keys of user has become a threat to the security of computing systems.It has become a common security requirement that a cryptographic scheme should withstand various leakage attacks.In the real life,an adversary can break the security of cryptography primitive by performing continuous leakage attacks.Although,some research on the leakage-resilient cryptography had been made,there are still some remaining issued in previous attempts.The identity-based encryption(IBE)constructions were designed in the bounded-leakage model,and might not be able to meet their claimed security under the continuous-leakage attacks.In the real applications,the leakage is unbounded.That is,a practical cryptography scheme should keep its original security in the continuous leakage setting.The previous continuous leakage-resilient IBE schemes either only achieve chosen-plaintext attacks security or the chosen-ciphertext attacks(CCA)security is proved in the selective identity model.Aiming to solve these problems,in this paper,we show how to construct the continuous leakage-resilient IBE scheme,and the scheme’s adaptive CCA security is proved in the standard model based on the hardness of decisional bilinear Diffie-Hellman exponent assumption.For any adversary,all elements in the ciphertext are random,and an adversary cannot obtain any leakage on the private key of user from the corresponding given ciphertext.Moreover,the leakage parameter of our proposal is independent of the plaintext space and has a constant size.

A lightweight symmetric image encryption cryptosystem in wavelet domain based on an improved sine map

In the era of big data,the number of images transmitted over the public channel increases exponentially.As a result,it is crucial to devise the efficient and highly secure encryption method to safeguard the sensitive image.In this paper,an improved sine map(ISM)possessing a larger chaotic region,more complex chaotic behavior and greater unpredictability is proposed and extensively tested.Drawing upon the strengths of ISM,we introduce a lightweight symmetric image encryption cryptosystem in wavelet domain(WDLIC).The WDLIC employs selective encryption to strike a satisfactory balance between security and speed.Initially,only the low-frequency-low-frequency component is chosen to encrypt utilizing classic permutation and diffusion.Then leveraging the statistical properties in wavelet domain,Gaussianization operation which opens the minds of encrypting image information in wavelet domain is first proposed and employed to all sub-bands.Simulations and theoretical analysis demonstrate the high speed and the remarkable effectiveness of WDLIC.

An Identity-Based Encryption Scheme with Compact Ciphertexts

This paper proposes an identity-based encryption scheme with the help of bilinear pairings, where the identity information of a user functions as the user＇s public key. The advantage of an identity-based public key system is that it can avoid public key certificates and certificate management. Our identity-based encryption scheme enjoys short ciphertexts and provable security against chosen-ciphertext attack （CCA）.

A chaotic hierarchical encryption/watermark embedding scheme for multi-medical images based on row-column confusion and closed-loop bi-directional diffusion

Security during remote transmission has been an important concern for researchers in recent years.In this paper,a hierarchical encryption multi-image encryption scheme for people with different security levels is designed,and a multiimage encryption(MIE)algorithm with row and column confusion and closed-loop bi-directional diffusion is adopted in the paper.While ensuring secure communication of medical image information,people with different security levels have different levels of decryption keys,and differentiated visual effects can be obtained by using the strong sensitivity of chaotic keys.The highest security level can obtain decrypted images without watermarks,and at the same time,patient information and copyright attribution can be verified by obtaining watermark images.The experimental results show that the scheme is sufficiently secure as an MIE scheme with visualized differences and the encryption and decryption efficiency is significantly improved compared to other works.

Properties of Self-recoverable Mechanoluminescence Phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+) and Its Information Encryption Application

A novel self-recoverable mechanoluminescent phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+) was developed by the high-tem-perature solid-state reaction method,and its luminescence properties were investigated.Ca_(5)Ga_(6)O_(14)∶Eu^(3+)can produce red mechanoluminescence,and importantly,it shows good repeatability.The mechanoluminescence of Ca_(5)Ga_(6)O_(14)∶Eu^(3+) results from the piezoelectric field generated inside the material under stress,rather than the charge carriers stored in the traps,which can be confirmed by the multiple cycles of mechanoluminescence tests and heat treatment tests.The mechanoluminescence color can be turned from red to green by co-doping varied concentrations of Tb^(3+),which may be meaningful for encrypted letter writing.The encryption scheme for secure communication was devised by harnessing mechanoluminescence patterns in diverse shapes and ASCII codes,which shows good encryption performance.The results suggest that the mechanoluminescence phosphor Ca_(5)Ga_(6)O_(14)∶Eu^(3+),Tb^(3+)may be applied to the optical information encryption.

Two-dimensional-lag complex logistic map with complex parameters and its encryption application

With the rapid development of internet technology,security protection of information has become more and more prominent,especially information encryption.Considering the great advantages of chaotic encryption,we propose a 2D-lag complex logistic map with complex parameters(2D-LCLMCP)and corresponding encryption schemes.Firstly,we present the model of the 2D-LCLMCP and analyze its chaotic properties and system stability through fixed points,Lyapunov exponent,bifurcation diagram,phase diagram,etc.Secondly,a block cipher algorithm based on the 2D-LCLMCP is proposed,the plaintext data is preprocessed using a pseudorandom sequence generated by the 2D-LCLMCP.Based on the generalized Feistel cipher structure,a round function F is constructed using dynamic S-box and DNA encoding rules as the core of the block cipher algorithm.The generalized Feistel cipher structure consists of two F functions,four XOR operations,and one permutation operation per round.The symmetric dynamic round keys that change with the plaintext are generated by the 2D-LCLMCP.Finally,experimental simulation and performance analysis tests are conducted.The results show that the block cipher algorithm has low complexit,good diffusion and a large key space.When the block length is 64 bits,only six rounds of encryption are required to provide sufficient security and robustness against cryptographic attacks.

A Linked List Encryption Scheme for Image Steganography without Embedding

Information steganography has received more and more attention from scholars nowadays,especially in the area of image steganography,which uses image content to transmit information and makes the existence of secret information undetectable.To enhance concealment and security,the Steganography without Embedding(SWE)method has proven effective in avoiding image distortion resulting from cover modification.In this paper,a novel encrypted communication scheme for image SWE is proposed.It reconstructs the image into a multi-linked list structure consisting of numerous nodes,where each pixel is transformed into a single node with data and pointer domains.By employing a special addressing algorithm,the optimal linked list corresponding to the secret information can be identified.The receiver can restore the secretmessage fromthe received image using only the list header position information.The scheme is based on the concept of coverless steganography,eliminating the need for any modifications to the cover image.It boasts high concealment and security,along with a complete message restoration rate,making it resistant to steganalysis.Furthermore,this paper proposes linked-list construction schemeswithin theproposedframework,which caneffectively resist a variety of attacks,includingnoise attacks and image compression,demonstrating a certain degree of robustness.To validate the proposed framework,practical tests and comparisons are conducted using multiple datasets.The results affirm the framework’s commendable performance in terms of message reduction rate,hidden writing capacity,and robustness against diverse attacks.