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.

Public-Key Encryption In The Standard Model Against Strong Leakage Adversary

2020 ◽  
Vol 63 (12) ◽  
pp. 1904-1914
Author(s):  
Janaka Alawatugoda
Keyword(s):  
Standard Model ◽  
Building Blocks ◽  
Public Key ◽  
Log P ◽  
Encryption Scheme ◽  
Public Key Encryption ◽  
Security Parameter ◽  
The Standard Model ◽  
Encryption Schemes ◽  
Leakage Resilient

Abstract Over the years, security against adaptively chosen-ciphertext attacks (CCA2) is considered as the strongest security definition for public-key encryption schemes. With the uprise of side-channel attacks, new security definitions are proposed, addressing leakage of secret keys together with the standard CCA2 definition. Among the new security definitions, security against continuous and after-the-fact leakage-resilient CCA2 can be considered as the strongest security definition, which is called as security against (continuous) adaptively chosen-ciphertext leakage attacks (continuous CCLA2). In this paper, we present a construction of a public-key encryption scheme, namely LR-PKE, which satisfies the aforementioned security definition. The security of our public-key encryption scheme is proven in the standard model, under decision BDH assumption. Thus, we emphasize that our public-key encryption scheme LR-PKE is (continuous) CCLA2-secure in the standard model. For our construction of LR-PKE, we have used a strong one-time signature scheme and a leakage-resilient refreshing protocol as underlying building blocks. The leakage bound is $0.15n\log p -1$ bits per leakage query, for a security parameter $k$ and a statistical security parameter $n$, such that $\log p \geq k$ and $n$ is a function of $k$. It is possible to see that LR-PKE is efficient enough to be used for real-world usage.

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 An Indistinguishably Secure Function Encryption Scheme

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Ping Zhang ◽  
Yamin Li ◽  
Muhua Liu
Keyword(s):  
Public Key ◽  
Proof System ◽  
Encryption Scheme ◽  
Symmetric Encryption ◽  
Public Key Encryption ◽  
The Public ◽  
Commitment Scheme

In this work, we first design a function encryption scheme by using key encapsulation. We combine public key encryption with symmetric encryption to implement the idea of key encapsulation. In the key encapsulation, we use a key to turn a message (plaintext) into a ciphertext by symmetric encryption, and then we use public key encryption to turn this key into another ciphertext. In the design of function encryption scheme, we use the public key encryption system, symmetric encryption system, noninteractive proof system, indistinguishable obfuscator, and commitment scheme. Finally, we prove the indistinguishable security of our function encryption scheme.

Weak leakage resilient extractable hash proof system and construction for weak leakage resilient CCA-secure public-key encryption

2015 ◽  
Vol 7 (3/4) ◽  
pp. 216
Author(s):  
Chengyu Hu ◽  
Zuoxia Yu ◽  
Rupeng Yang ◽  
Qiuliang Xu ◽  
Yongbin Zhou ◽  
...  
Keyword(s):  
Public Key ◽  
Proof System ◽  
Public Key Encryption ◽  
Leakage Resilient ◽  
Hash Proof System

Public key encryption with equality test via hash proof system

2019 ◽  
Vol 795 ◽  
pp. 20-35
Author(s):  
Ming Zeng ◽  
Jie Chen ◽  
Kai Zhang ◽  
Haifeng Qian
Keyword(s):  
Public Key ◽  
Proof System ◽  
Public Key Encryption ◽  
Hash Proof System ◽  
Equality Test
Sign in / Sign up

Export Citation Format

Share Document