Lattice Based Group Key Exchange Protocol in the Standard Model

2021 ◽  
Author(s):  
Parhat Abla
Keyword(s):  
Standard Model ◽  
Quantum Algorithms ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Key Exchange ◽  
Session Key ◽  
Group Key ◽  
Group Key Exchange ◽  
The Standard Model ◽  
Group Members

Group key exchange schemes allow group members to agree on a session key. Although there are many works on constructing group key exchange schemes, but most of them are based on algebraic problems which can be solved by quantum algorithms in polynomial time. Even if several works considered lattice based group key exchange schemes, believed to be post-quantum secure, but only in the random oracle model. In this work, we propose a group key exchange scheme based on ring learning with errors problem. On contrast to existing schemes, our scheme is proved to be secure in the standard model. To achieve this, we define and instantiate multi-party key reconciliation mechanism. Furthermore, using known compiler with lattice based signature schemes, we can achieve authenticated group key exchange with postquantum security.

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 A Generic Framework for Accountable Optimistic Fair Exchange Protocol

Symmetry ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 285
Author(s):  
Jia-Ch’ng Loh ◽  
Swee-Huay Heng ◽  
Syh-Yuan Tan
Keyword(s):  
Standard Model ◽  
Random Oracle Model ◽  
Building Blocks ◽  
Random Oracle ◽  
Fair Exchange ◽  
Generic Framework ◽  
The Standard Model ◽  
Security Properties ◽  
Optimistic Fair Exchange ◽  
The One

Optimistic Fair Exchange protocol was designed for two parties to exchange in a fair way where an arbitrator always remains offline and will be referred only if any dispute happens. There are various optimistic fair exchange protocols with different security properties in the literature. Most of the optimistic fair exchange protocols satisfy resolution ambiguity where a signature signed by the signer is computational indistinguishable from the one resolved by the arbitrator. Huang et al. proposed the first generic framework for accountable optimistic fair exchange protocol in the random oracle model where it possesses resolution ambiguity and is able to reveal the actual signer when needed. Ganjavi et al. later proposed the first generic framework in the standard model. In this paper, we propose a new generic framework for accountable optimistic fair exchange protocol in the standard model using ordinary signature, convertible undeniable signature, and ring signature scheme as the underlying building blocks. We also provide an instantiation using our proposed generic framework to obtain an efficient pairing-based accountable optimistic fair exchange protocol with short signature.

Large Universe CCA2 CP-ABE With Equality and Validity Test in the Standard Model

2020 ◽  
Author(s):  
Cong Li ◽  
Qingni Shen ◽  
Zhikang Xie ◽  
Xinyu Feng ◽  
Yuejian Fang ◽  
...  
Keyword(s):  
Standard Model ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Fine Grained ◽  
Validity Check ◽  
Attribute Based Encryption ◽  
The Standard Model ◽  
Series Of Experiments ◽  
Ciphertext Policy ◽  
Chosen Ciphertext Security

Abstract Attribute-based encryption with equality test (ABEET) simultaneously supports fine-grained access control on the encrypted data and plaintext message equality comparison without decrypting the ciphertexts. Recently, there have been several literatures about ABEET proposed. Nevertheless, most of them explore the ABEET schemes in the random oracle model, which has been pointed out to have many defects in practicality. The only existing ABEET scheme in the standard model, proposed by Wang et al., merely achieves the indistinguishable against chosen-plaintext attack security. Considering the aforementioned problems, in this paper, we propose the first direct adaptive chosen-ciphertext security ciphertext-policy ABEET scheme in the standard model. Our method only adopts a chameleon hash function and adds one dummy attribute to the access structure. Compared with the previous works, our scheme achieves the security improvement, ciphertext validity check and large universe. Besides, we further optimize our scheme to support the outsourced decryption. Finally, we first give the detailed theoretical analysis of our constructions in computation and storage costs, then we implement our constructions and carry out a series of experiments. Both results indicate that our constructions are more efficient in Setup and Trapdoor and have the shorter public parameters than the existing ABEET ones do.

Double-authentication-preventing signatures in the standard model

2021 ◽  
pp. 1-36
Author(s):  
Dario Catalano ◽  
Georg Fuchsbauer ◽  
Azam Soleimanian
Keyword(s):  
Standard Model ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Polynomial Size ◽  
The Standard Model ◽  
Generic Construction ◽  
Self Enforcement ◽  
Digital Signature Scheme ◽  
Chameleon Hash ◽  
Main Construction

A double-authentication preventing signature (DAPS) scheme is a digital signature scheme equipped with a self-enforcement mechanism. Messages consist of an address and a payload component, and a signer is penalized if she signs two messages with the same addresses but different payloads. The penalty is the disclosure of the signer’s signing key. Most of the existing DAPS schemes are proved secure in the random oracle model (ROM), while the efficient ones in the standard model only support address spaces of polynomial size. We present DAPS schemes that are efficient, secure in the standard model under standard assumptions and support large address spaces. Our main construction builds on vector commitments (VC) and double-trapdoor chameleon hash functions (DCH). We also provide a DAPS realization from Groth–Sahai (GS) proofs that builds on a generic construction by Derler et al., which they instantiate in the ROM. The GS-based construction, while less efficient than our main one, shows that a general yet efficient instantiation of DAPS in the standard model is possible. An interesting feature of our main construction is that it can be easily modified to guarantee security even in the most challenging setting where no trusted setup is provided. To the best of our knowledge, ours seems to be the first construction achieving this in the standard model.

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