Securing Public Key Encryption Against Adaptive Chosen Ciphertext Attacks

2018 ◽  
pp. 134-144
Author(s):  
Kannan Balasubramanian
Keyword(s):  
Partial Information ◽  
Hash Functions ◽  
Public Key ◽  
Public Key Encryption ◽  
Public Key Cryptosystems ◽  
Active Attacks ◽  
Chosen Ciphertext Attack ◽  
Decryption Oracle

To deal with active attacks in public key encryptions, the notion of security against an adaptive chosen ciphertext attack has been defined by Researchers. If an adversary can inject messages into a network, these messages may be ciphertexts, and the adversary may be able to extract partial information about the corresponding cleartexts through its interaction with parties in the network. The Security against chosen ciphertext attack is defined using an “decryption oracle.” Given an encryption of a message the “ciphertext” we want to guarantee that the adversary cannot obtain any partial information about the message. A method of securing Public Key Cryptosystems using hash functions is described in this chapter.

Public-Key Encryption

2017 ◽  
Author(s):  
Keith M. Martin
Keyword(s):  
Elliptic Curve ◽  
Public Key Cryptography ◽  
Public Key ◽  
Public Key Encryption ◽  
Hybrid Encryption ◽  
Public Key Cryptosystems ◽  
Encryption And Decryption ◽  
Encryption Schemes ◽  
Hard Problems ◽  
Set Up

In this chapter, we introduce public-key encryption. We first consider the motivation behind the concept of public-key cryptography and introduce the hard problems on which popular public-key encryption schemes are based. We then discuss two of the best-known public-key cryptosystems, RSA and ElGamal. For each of these public-key cryptosystems, we discuss how to set up key pairs and perform basic encryption and decryption. We also identify the basis for security for each of these cryptosystems. We then compare RSA, ElGamal, and elliptic-curve variants of ElGamal from the perspectives of performance and security. Finally, we look at how public-key encryption is used in practice, focusing on the popular use of hybrid encryption.

scholarly journals CCA Secure Public Key Encryption against After-the-Fact Leakage without NIZK Proofs

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yi Zhao ◽  
Kaitai Liang ◽  
Bo Yang ◽  
Liqun Chen
Keyword(s):  
State Model ◽  
Encryption Algorithm ◽  
Public Key ◽  
Public Key Encryption ◽  
Split State ◽  
Leakage Resilient ◽  
Traditional Sense ◽  
Definition Of ◽  
Lossy Trapdoor Functions ◽  
Chosen Ciphertext Attack

In leakage resilient cryptography, there is a seemingly inherent restraint on the ability of the adversary that it cannot get access to the leakage oracle after the challenge. Recently, a series of works made a breakthrough to consider a postchallenge leakage. They presented achievable public key encryption (PKE) schemes which are semantically secure against after-the-fact leakage in the split-state model. This model puts a more acceptable constraint on adversary’s ability that the adversary cannot query the leakage of secret states as a whole but the functions of several parts separately instead of prechallenge query only. To obtain security against chosen ciphertext attack (CCA) for PKE schemes against after-the-fact leakage attack (AFL), existing works followed the paradigm of “double encryption” which needs noninteractive zero knowledge (NIZK) proofs in the encryption algorithm. We present an alternative way to achieve AFL-CCA security via lossy trapdoor functions (LTFs) without NIZK proofs. First, we formalize the definition of LTFs secure against AFL (AFLR-LTFs) and all-but-one variants (ABO). Then, we show how to realize this primitive in the split-state model. This primitive can be used to construct AFLR-CCA secure PKE scheme in the same way as the method of “CCA from LTFs” in traditional sense.

On Public-Key Encryption Scheme Based on Chebyshev Maps

2011 ◽  
Vol 268-270 ◽  
pp. 1110-1114
Author(s):  
Lin Hua Zhang ◽  
Xiu Li Mao ◽  
Wan Yu Duan
Keyword(s):  
Theoretical Analysis ◽  
Chebyshev Polynomials ◽  
Experimental Results ◽  
Public Key ◽  
Encryption Scheme ◽  
Public Key Encryption ◽  
Public Key Cryptosystems

Due to the exceptionally desirable properties, Chebyshev polynomials have been recently proposed for designing public key cryptosystems. However, some proposed schemes were pointed out to be insecure and unpractical. In this paper, we analyze their defects, discretize the Chebyshev maps, generalize properties of Chebyshev polynomials and design an improved scheme. Theoretical analysis shows that it possesses higher security than RSA and experimental results shows it can be implemented easily.

scholarly journals Universal Hash Proofs and a Paradigm for Adaptive Chosen Ciphertext Secure Public-Key Encryption

2001 ◽  
Vol 8 (37) ◽  
Author(s):  
Ronald Cramer ◽  
Victor Shoup
Keyword(s):  
Special Kind ◽  
Public Key ◽  
Proof System ◽  
Reasonable Assumption ◽  
Encryption Scheme ◽  
Public Key Encryption ◽  
Proof Systems ◽  
Encryption Schemes ◽  
Hash Proof System ◽  
Chosen Ciphertext Attack

We present several new and fairly practical public-key encryption schemes and prove them secure against adaptive chosen ciphertext attack. One scheme is based on Paillier's Decision Composite Residuosity (DCR) assumption, while another is based in the classical Quadratic Residuosity (QR) assumption. The analysis is in the standard cryptographic model, i.e., the security of our schemes does not rely on the Random Oracle model.<br /> <br />We also introduce the notion of a universal hash proof system. Essentially, this is a special kind of non-interactive zero-knowledge proof system for an NP language. We do not show that universal hash proof systems exist for all NP languages, but we do show how to construct very efficient universal hash proof systems for a general class of group-theoretic language membership problems.<br /> <br />Given an efficient universal hash proof system for a language with certain natural cryptographic indistinguishability properties, we show how to construct an efficient public-key encryption schemes secure against adaptive chosen ciphertext attack in the standard model. Our construction only uses the universal hash proof system as a primitive: no other primitives are required, although even more efficient encryption schemes can be obtained by using hash functions with appropriate collision-resistance properties. We show how to construct efficient universal hash proof systems for languages related to the DCR and QR assumptions. From these we get corresponding public-key encryption schemes that are secure under these assumptions. We also show that the Cramer-Shoup encryption scheme (which up until now was the only practical encryption scheme that could be proved secure against adaptive chosen ciphertext attack under a reasonable assumption, namely, the Decision Diffie-Hellman assumption) is also a special case of our general theory.

Pairing-Free Identity-Based Encryption with Authorized Equality Test in Online Social Networks

2019 ◽  
Vol 30 (04) ◽  
pp. 647-664
Author(s):  
Libing Wu ◽  
Yubo Zhang ◽  
Kim-Kwang Raymond Choo ◽  
Debiao He
Keyword(s):  
Social Networking ◽  
Online Social Networks ◽  
Keyword Search ◽  
Public Key ◽  
Encryption Scheme ◽  
Public Key Encryption ◽  
Identity Based Encryption ◽  
Identity Based ◽  
Equality Test ◽  
Chosen Ciphertext Attack

Online social networking applications have become more and more popular in the advance of the technological age. Much of our personal information has been disclosed in social networking activities and privacy-preserving still remains a research challenge in social network. Public key encryption scheme with equality test(PKEET), which is an extension of public key encryption with keyword search (PEKS), seems to be a solution. PKEET enables the tester to check whether two given ciphertexts are derived from the same plaintext. Recently, Zhu et al. proposed a pairing-free public key encryption scheme with equality test based on the traditional public key cryptosystem. However, it suffers from certificates management issue. In this paper, we propose a pairing-free identity-based encryption scheme with authorized equality test(PF-IBEAET). The PF-IBEAET scheme also provides fine-grained authorizations. We prove that the scheme is one way secure against chosen identity and chosen ciphertext attack (OW-ID-CCA) and indistinguishable against chosen-identity and chosen-ciphertext attack (IND-ID-CCA) in the random oracle model (ROM). Performance analysis shows that the scheme achieves a better performance than similar schemes.

scholarly journals Mutual query data sharing protocol for public key encryption through chosen-ciphertext attack in cloud environment

2022 ◽  
Vol 12 (1) ◽  
pp. 853
Author(s):  
Tarasvi Lakum ◽  
Barige Thirumala Rao
Keyword(s):  
Data Sharing ◽  
Public Key ◽  
Communication Overhead ◽  
Public Key Encryption ◽  
Cloud Environment ◽  
Diffie Hellman ◽  
User Data ◽  
Time Limitations ◽  
Chosen Ciphertext Attack ◽  
Existing Data

<p><span>In this paper, we are proposing a mutual query data sharing protocol (MQDS) to overcome the encryption or decryption time limitations of exiting protocols like Boneh, rivest shamir adleman (RSA), Multi-bit transposed ring learning parity with noise (TRLPN), ring learning parity with noise (Ring-LPN) cryptosystem, key-Ordered decisional learning parity with noise (kO-DLPN), and KD_CS protocol’s. Titled scheme is to provide the security for the authenticated user data among the distributed physical users and devices. The proposed data sharing protocol is designed to resist the chosen-ciphertext attack (CCA) under the hardness solution for the query shared-strong diffie-hellman (SDH) problem. The evaluation of proposed work with the existing data sharing protocols in computational and communication overhead through their response time is evaluated.</span></p>

A New Framework of IND-CCA Secure Public Key Encryption with Keyword Search

2020 ◽  
Vol 63 (12) ◽  
pp. 1849-1858 ◽  
Author(s):  
Sha Ma ◽  
Qiong Huang
Keyword(s):  
Keyword Search ◽  
Public Key ◽  
Public Key Encryption ◽  
Diffie Hellman ◽  
The Standard Model ◽  
Identity Based ◽  
Hash Key ◽  
Chosen Ciphertext Attack ◽  
Security Notion ◽  
New Framework

Abstract In the era of cloud computing, public key encryption with keyword search (PEKS) is an extremely useful cryptographic tool for searching on encryption data, whose strongest security notion is indistinguishability encryption against chosen ciphertext attack (ind-cca). Adballa et al. presented a transformation from identity based encryption (IBE) to PEKS in the Theory of Cryptography Conference 2010. This paper proposes a new framework of ind-cca secure PEKS in the standard model. Our main technical tool is a newly introduced notion of smooth projective hash function with key mapping, in which the hash key hk is mapped into another mapping projection key mhp besides the classical projection key hp. Finally, we provide an instantiation of our framework based on symmetric eXternal Diffie–Hellman assumption.

On the KDM-CCA Security from Partial Trapdoor One-Way Family in the Random Oracle Model

2019 ◽  
Vol 62 (8) ◽  
pp. 1232-1245
Author(s):  
Jinyong Chang ◽  
Genqing Bian ◽  
Yanyan Ji ◽  
Maozhi Xu
Keyword(s):  
Slight Modification ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Public Key ◽  
Public Key Encryption ◽  
Know How ◽  
One Way Function ◽  
Chosen Ciphertext Attack

Abstract In PKC 2000, Pointcheval presented a generic technique to make a highly secure cryptosystem from any partially trapdoor one-way function in the random oracle model. More precisely, any suitable problem providing a one-way cryptosystem can be efficiently derived into a chosen-ciphertext attack (CCA) secure public key encryption (PKE) scheme. In fact, the overhead only consists of two hashing and a XOR. In this paper, we consider the key-dependent message (KDM) security of the Pointcheval’s transformation. Unfortunately, we do not know how to directly prove its KDM-CCA security because there are some details in the proof that we can not bypass. However, a slight modification of the original transformation (we call twisted Pointcheval’s scheme) makes it possible to obtain the KDM-CCA security. As a result, we prove that the twisted Pointcheval’s scheme achieves the KDM-CCA security without introducing any new assumption. That is, we can construct a KDM-CCA secure PKE scheme from partial trapdoor one-way injective family in the random oracle model.

Sign in / Sign up

Export Citation Format

Share Document