Threshold Encryption Scheme Research Articles

Multi-recipient and threshold encryption based on hidden multipliers

Let $S$ be a pool of $s$ parties and Alice be the dealer. In this paper, we propose a scheme that allows the dealer to encrypt messages in such a way that only one authorized coalition of parties (which the dealer chooses depending on the message) can decrypt. At the setup stage, each of the parties involved in the process receives an individual key from the dealer. To decrypt information, an authorized coalition of parties must work together to use their keys. Based on this scheme, we propose a threshold encryption scheme. For a given message $f$ the dealer can choose any threshold $m = m(f).$ More precisely, any set of parties of size at least $m$ can evaluate $f$; any set of size less than $m$ cannot do this. Similarly, the distribution of keys among the included parties can be done in such a way that authorized coalitions of parties will be given the opportunity to put a collective digital signature on any documents. This primitive can be generalized to the dynamic setting, where any user can dynamically join the pool $S$. In this case the new user receives a key from the dealer. Also any user can leave the pool $S$. In both cases, already distributed keys of other users do not change. The main feature of the proposed schemes is that for a given $s$ the keys are distributed once and can be used multiple times. The proposed scheme is based on the idea of hidden multipliers in encryption. As a platform, one can use both multiplicative groups of finite fields and groups of invertible elements of commutative rings, in particular, multiplicative groups of residue rings. We propose two versions of this scheme.

Data Security Analysis Against Chosen Ciphertext Secure Public Key Attack Using Threshold Encryption Scheme

A public key encryption cryptography system can be utilized to generate ciphertext of a message using a public key. However, this public key encryption cryptography system cannot be utilized if you want to generate ciphertext using several different keys. Solving the problems above can use the Chosen Ciphertext Secure Public Key Threshold Encryption scheme but are the securities from Threshold Encryption really strong in securing messages, therefore the above problems can be analyzed for Data Security Against Chosen Ciphertext Secure Public Key Attacks Using Threshold Encryption Schemes. The work process starts from Setup which functions to generate the server's private key and public key. Then, the process is continued with ShareKeyGen which functions to generate private keys based on the user's identity. After that, the process continues with ShareVerify which serves to verify the key generated from the ShareKeyGen process. The process will be continued again with Combine which serves to generate a private key that will be used in the decryption process. After that, the process will continue with the encryption process of the secret message. The ciphertext obtained will be sent to the recipient. The receiver verifies the ciphertext by running ValidateCT. Finally, the ciphertext is decrypted by running Decrypt. The software created can be used to display the workflow process of the Threshold schema. In addition, it makes it easier to test intercepts of ciphertext messages to other users so that generic securities analysis is carried out in testing the resulting ciphertext. The results of the implementation of Threshold Encryption algorithm scheme can protect important personal data, because it involves human rights, namely the right to access, the right to delete, the right to correct, the right to be corrected and the right to transfer personal data safely from attacks.

Tenant-Led Ciphertext Information Flow Control for Cloud Virtual Machines

When users upload their private data to the cloud, they lose control of the data stored in the cloud server. If the cloud system cannot provide an effective security mechanism to protect the data, the consequent data leakage issue will hinder the development of cloud computing. Conventional access control and encryption technologies cannot effectively control the propagation of tenant private data in the system. The mandatory one-way information flow control model is limited by the complexity of the cloud environment, and it is difficult to effectively protect private data stored in the cloud. To solve the above problems, this article proposes a tenant-led ciphertext information flow control method for cloud virtual machines. Through the design of a decentralized information flow control security policy, a secret-domain key management scheme, and a multi-ID-based threshold encryption scheme, the information flow control strategies of taint infection, secret-level reduction, and ability propagation are realized in a ciphertext form, which can effectively prevent malicious users inside and outside the system from illegally reading private data. The feasibility of this method is verified by a security proof and an experiment.

A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications

A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications

Efficient RSA Key Generation and Threshold Paillier in the Two-Party Setting

The problem of generating an RSA composite in a distributed manner without leaking its factorization is particularly challenging and useful in many cryptographic protocols. Our first contribution is the first non-generic fully simulatable protocol for distributively generating an RSA composite with security against malicious behavior. Our second contribution is a complete Paillier (in: EUROCRYPT, pp 223–238, 1999) threshold encryption scheme in the two-party setting with security against malicious attacks. We further describe how to extend our protocols to the multiparty setting with dishonest majority. Our RSA key generation protocol is comprised of the following subprotocols: (i) a distributed protocol for generation of an RSA composite and (ii) a biprimality test for verifying the validity of the generated composite. Our Paillier threshold encryption scheme uses the RSA composite for the public key and is comprised of the following subprotocols: (i) a distributed generation of the corresponding secret key shares and (ii) a distributed decryption protocol for decrypting according to Paillier.

Editorial preface for the special issue “Advances in security, privacy and trust technologies”

With the fast development of Internet technologies, the information and communication systems are continuously facing new security, trust and privacy challenges. Indeed, the potentially invasive nature of the information has implications on privacy of the users and their online activity such as transactions. Likewise, the implicit reliance on technology to make decisions on one’s behalf makes essential to study new mechanisms for expressing and reasoning about trust. This special issue brings together research articles covering diverse aspects of security, privacy and trust in computer and networked-based information systems, including privacy concerns, tools to help secure information, methods for development and assessment of trustworthy systems, analysis of vulnerabilities and attacks, trends and new developments, secure operating systems and applications, security issues in wireless networks and pervasive systems, design and test strategies for secure and survivable systems, and cryptology, among others. The papers of the special issue are selected based on strict review results, where papers went through three rounds of review and revision. As a result, nine papers were selected and are arranged in the special issue as follows. Xiong et al. in the first paper ‘‘The finite volume element method for a parameter identification problem’’ use finite volume element method to solve a parameter identification problem of parabolic equations with over-specified data. The authors provide the numerical scheme of the unknown function and control parameters and obtain the error estimates of approximate solution. The proposed method is experimentally evaluated and compared with the exact solution to confirm the good accuracy of the presented scheme. The second paper by Chen et al. ‘‘An Opinion Mining Framework For Cantonese Reviews’’, analyze opinion mining for Cantonese language. The authors motivate the need to construct a particular lexical database for Cantonese and explore some Cantonese special written-tradition rules and incorporate them into the feature-based opinion summarization system framework. The experimental results show that the proposed framework significantly outperforms the traditional Mandarin sentiment analysis method using ICTCLAS. In the third paper ‘‘A Secure Remote Data Integrity Checking Cloud Storage System from Threshold Encryption’’, Yao et al. study the confidentiality and integrity issues in cloud storage system. The authors address the privacy issue of decentralized cloud storage system using threshold cryptography. The threshold encryption scheme is therefore integrated with a secure decentralized erasure code to form a secure cloud storage system. Zhang et al. in the fourth paper ‘‘How to build a faster private information retrieval protocol’’, propose a secure multi-bit homomorphic encryption scheme based on Learning With Errors over Rings (RLWE) assumption. The authors use canonical embedding to transform ring & Fatos Xhafa fatos@cs.upc.edu

A secure remote data integrity checking cloud storage system from threshold encryption

The confidentiality and integrity are the most important issues in cloud storage system. We address the privacy issue of decentralized cloud storage system using threshold cryptography. Once the user uploads his data and deletes the local copy, he might lost the full control of the data. The major challenges of designing this cloud storage system are to provide a better privacy guarantee and ensure the integrity of data at untrusted servers in distributed cloud storage system. To achieve this goal, we propose a threshold encryption scheme and integrate it with a secure decentralized erasure code to form a secure cloud storage system, where the user generates a secret parameter participated in system encryption and decryption of plaintext blocks in the combine process. So our systems can prevent cloud storage servers from modifying data by providing remote data check and meets the requirements of data robustness, confidentiality and integrity.

Efficient fully homomorphic encryption from RLWE with an extension to a threshold encryption scheme

In this paper, we present an effective fully homomorphic encryption (FHE) from ring learning with errors (RLWE) assumption without using Gentry’s standard squashing and bootstrapping techniques. Our FHE scheme is to modify the recent FHE scheme of Brakerski. We use the re-linearization technique to reduce the length of ciphertext considerably, and use the modulus reduction technique to manage the noise level and decrease the decryption complexity without introducing additional assumptions. Furthermore, with the key-homomorphic property, we extend our FHE scheme to a threshold fully homomorphic encryption (TFHE), which allows parties to cooperatively decrypt a ciphertext without learning anything but the plaintext. The TFHE scheme can be protected from related-key attacks, as long as we add extra smudging noise during sensitive operations.

Secure Computation Protocol for Testing the Inclusion Relation of Sets

A set operation problem is considered in the secure computation setting. Player A has a secret set SA and player B has a secret set SB,where SA and SB belong to a universe. They want to know if SA includes SB without leaking anything else about their secret sets. Three protocols of different levels of security and efficiency are proposed for this problem. The first protocol can be based on the so-called Superposed Encryption scheme or threshold encryption scheme. Let NB be the size of set SB,the first protocol needs NB rounds of communication. The other two protocols are based on standard public-key encryption schemes with additively homomorphic property,and need only one round of communication. Compared to previous results,the first two protocols use a new technique of representing sets,and the third protocol avoids threshold decryption in the output phase,and is more efficient.

A secure two‐factor authentication scheme for single sign‐on services

AbstractWe present a novel single sign‐on (SSO) scheme known as secure distributed SSO (SeDSSO). SeDSSO provides secure fault‐tolerant authentication using threshold key encryption with a distributed authentication service. The authentication service consists of n total authentication servers utilizing a (t, n) threshold encryption scheme, where t distinct server‐signed messages are required to generate a message signed by the service. SeDSSO provides secure portable identities by defining a two‐factor identity that uses both a username/password and a unique USB device. The combination of a distributed authentication service and two‐factor identities allows SeDSSO to securely authenticate users in any environment. Copyright © 2008 John Wiley & Sons, Ltd.