A Provably Secure E-Cash Scheme with Loss-Tracing

2013 ◽  
Vol 748 ◽  
pp. 958-966
Author(s):  
Bin Lian ◽  
Gong Liang Chen ◽  
Jian Hua Li
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Third Party ◽  
Trusted Third Party ◽  
Security Proofs ◽  
Almost All ◽  
Practical Scheme ◽  
Provably Secure

E-cash should be spent anonymously in normal circumstances, while in many schemes, the trusted authority is the only one who acts as customer-tracer and e-coin-tracer for preventing illegal transactions, but it is not the case in the reality. In our practical scheme, the bank traces double-spenders without the help of others, and the trusted third party traces e-coins and the owner only when the customer is involved in crimes. When customers lose their e-coins for some reasons, the loss-tracing can be triggered in our scheme which is neglected by almost all existing schemes, so if the lost coins haven't been spent by anyone, the customers can get the refund from the bank. And then the security proofs for our E-cash scheme are provided in the random oracle model.

A Provably Secure Certificate-Based Signature Scheme with Bilinear Pairings

2010 ◽  
Vol 439-440 ◽  
pp. 1271-1276 ◽  
Author(s):  
Jian Hong Zhang ◽  
Hua Chen ◽  
Yi Xian Yang
Keyword(s):  
Discrete Logarithm ◽  
Random Oracle Model ◽  
Bilinear Pairings ◽  
Random Oracle ◽  
Third Party ◽  
Maintenance Cost ◽  
Signature Scheme ◽  
Key Escrow ◽  
Identity Based ◽  
Provably Secure

Traditional public key cryptosystem (PKC) requires high maintenance cost for certificate management. Although, identity based cryptosystem (IBC) reduces the overhead of management, it suffers from the drawback of key escrow. Certificate-based cryptosystem solves certificate revocation problem and eliminate third party queries in the traditional PKI. In addition, it also solves the inherent key escrow problem in the IBC. In this paper, we proposed an efficient certificate-based signature and the result shows that the scheme is provable secure against two game attacks of certificate-based signature in the random oracle model. The security is closely related to the difficulty of solving the discrete logarithm problem.

scholarly journals A Secure Multimedia Data Sharing Scheme for Wireless Network

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Liming Fang ◽  
Liang Liu ◽  
Jinyue Xia ◽  
Maosheng Sun
Keyword(s):  
Wireless Network ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Multimedia Data ◽  
Third Party ◽  
Wireless Multimedia ◽  
Cloud Platform ◽  
Trusted Third Party ◽  
Cloud Server ◽  
Share Data

A large number of wireless devices like WiFi cameras and 4G robots have been deployed in the rapidly growing wireless network such as Internet of Things. All of the devices (sensors) are collecting and analyzing multimedia data all the time while they are actively working, and it is also required to share data among these the sensors. Typically, the wireless data is transmitted through the network gateway or the cloud platforms. In such a wireless environment, if there is no appropriate protection to the data, it is easy to cause potential data leakage. In reality, the owner of the sensor might only want to share the multimedia data stored in the sensor with a trusted third party (e.g., a family member or a coworker) through an internet gateway or the cloud platform. Ideally, the gateway or the cloud platform in the wireless network should transform one user’s encrypted data (wireless multimedia data) directly into another ciphertext under a set of new users (e.g., a trusted third party) without accessing the user’s plaintext data. In this work, a new secure notion called fuzzy-conditional proxy broadcast re-encryption (FC-PBRE) is presented to address the concern. In a FC-PBRE scheme, the proxy (the gateway or cloud server) uses a broadcast re-encryption key to re-encrypt the encrypted wireless multimedia data which can be decrypted by a set of delegatees if and only if the broadcast key’s conditional set W is close to the conditional set W′ of the ciphertext. With the FC-PBRE scheme, the wireless multimedia data is not disclosed and cannot be learnt by the proxy (the gateway or cloud server). In this paper, we first present the definition of security against chosen-ciphertext attacks for FC-PBRE. Second, we propose an efficient fuzzy-conditional proxy broadcast re-encryption scheme. Third, we prove that our FC-PBRE scheme is CCA-secure in the random oracle model based on the Decisional nBDHE assumption.

Tighter Security Proofs for GPV-IBE in the Quantum Random Oracle Model

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Shuichi Katsumata ◽  
Shota Yamada ◽  
Takashi Yamakawa
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Security Proofs

Another Attack on Tso's Short Signature Scheme Based on Bilinear Pairings

2011 ◽  
Vol 63-64 ◽  
pp. 785-788
Author(s):  
Fan Yu Kong ◽  
Lei Wu ◽  
Jia Yu
Keyword(s):  
Random Oracle Model ◽  
Bilinear Pairings ◽  
Random Oracle ◽  
Public Key ◽  
Signature Scheme ◽  
Short Signature ◽  
Provably Secure

In 2009, R. Tso et al. proposed an efficient pairing-based short signature scheme which is provably secure in the Random Oracle Model. In this paper, we propose a new key substitution attack on Raylin Tso et al.’s short signature scheme. For a given message and the corresponding valid signature, the malicious attacker can generate a substituted public key. Everyone verifies the signature successfully with the malicious attacker’s substituted public key. Therefore, Raylin Tso et al.’s short signature scheme has a security flaw in the multi-user setting.

Efficient Convertible User Designating Confirmer Partially Blind Signature with Provable Security

2011 ◽  
Vol 282-283 ◽  
pp. 307-311
Author(s):  
Li Zhen Ma
Keyword(s):  
Provable Security ◽  
Discrete Logarithm ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Blind Signature ◽  
Discrete Logarithm Problem ◽  
Public Key ◽  
Signature Schemes ◽  
Partially Blind Signature ◽  
Provably Secure

Any one who knows the signer’s public key can verify the validity of a given signature in partially blind signature schemes. This verifying universality may be used by cheats if the signed message is sensitive or personal. To solve this problem, a new convertible user designating confirmer partially blind signature, in which only the designated confirmer (designated by the user) and the user can verify and confirm the validity of given signatures and convert given signatures into publicly verifiable ones, is proposed. Compared with Huang et al.’s scheme, the signature size is shortened about 25% and the computation quantity is reduced about 36% in the proposed scheme. Under random oracle model and intractability of Discrete Logarithm Problem the proposed scheme is provably secure.

An Improved RSA-Based Certificateless Signature Scheme

2014 ◽  
Vol 687-691 ◽  
pp. 2165-2168
Author(s):  
Xue Dong Dong ◽  
Hui Min Lu
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Type I ◽  
Signature Scheme ◽  
The Public ◽  
Public Keys ◽  
Security Properties ◽  
Identity Based ◽  
Certificateless Signature ◽  
Provably Secure

Certificateless-based signature can eliminate the need of certificates in the Public Key Infrastructure and solve the inherent key escrow problem in the identity-based cryptography. In 2012 Zhang et al. [J. Zhang and J. Mao, An efficient RSA-based certificateless signature scheme, Journal of Systems and Software, vol. 85, pp. 638-642, 2012] proposed the first certificateless signature scheme based on RSA operations and showed that their scheme is provably secure in the random oracle model. However, He et al. [D. He, M.Khan, and S. Wu, On the security of a RSA-based certificateless signature scheme, International Journal of Network Security, vol.16, no.1, pp.78-80, 2014] recently showed that Zhang et al.'s scheme is insecure against a type I adversary who can replace users' public keys. In this paper, we propose an improved version based on RSA which not only keeps the original security properties of the signature, but also is secure against a type I adversary.

scholarly journals Practical generation of common random strings for secure multiparty computations over the Internet

2020 ◽  
Vol 8 (6) ◽  
pp. 01-15
Author(s):  
István Vajda
Keyword(s):  
Broadcast Channels ◽  
Third Party ◽  
The Internet ◽  
Random String ◽  
Coin Toss ◽  
Trusted Third Party ◽  
Malicious Adversary ◽  
Radio Broadcast ◽  
Secure Implementation ◽  
Provably Secure

It is known that most of the interesting multiparty cryptographic tasks cannot be implemented securely without trusted setup in a general concurrent network environment like the Internet. We need an appropriate trusted third party to solve this problem.  An important trusted setup is a public random string shared by the parties. We present a practical n-bit coin toss protocol for provably secure implementation of such setup. Our idea is inviting external peers into the execution of the protocol to establish an honest majority among the parties. We guarantee security in the presence of an unconditional, static, malicious adversary. Additionally, we present an original practical idea of using live public radio broadcast channels for the generation of common physical random source.  

scholarly journals Provably Secure Covert Communication on Blockchain

Cryptography ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 18 ◽  
Author(s):  
Juha Partala
Keyword(s):  
Hash Function ◽  
Random Oracle Model ◽  
Data Integrity ◽  
Random Oracle ◽  
Covert Communication ◽  
Smart Contracts ◽  
Cryptographic Hash Function ◽  
Rigorous Definition ◽  
Open Nature ◽  
Provably Secure

Blockchain is a public open ledger that provides data integrity in a distributed manner. It is the underlying technology of cryptocurrencies and an increasing number of related applications, such as smart contracts. The open nature of blockchain together with strong integrity guarantees on the stored data makes it a compelling platform for covert communication. In this paper, we suggest a method of securely embedding covert messages into a blockchain. We formulate a simplified ideal blockchain model based on existing implementations and devise a protocol that enables two parties to covertly communicate through the blockchain following that model. We also formulate a rigorous definition for the security and covertness of such a protocol based on computational indistinguishability. Finally, we show that our method satisfies this definition in the random oracle model for the underlying cryptographic hash function.

scholarly journals An Efficient and Provably-Secure Certificateless Proxy-Signcryption Scheme for Electronic Prescription System

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Li Li ◽  
Siqin Zhou ◽  
Kim-Kwang Raymond Choo ◽  
Xiaohong Li ◽  
Debiao He
Keyword(s):  
Random Oracle Model ◽  
Research Area ◽  
Random Oracle ◽  
Performance Evaluations ◽  
Electronic Prescription ◽  
Limited Bandwidth ◽  
Cryptographic Primitive ◽  
And Performance ◽  
Signcryption Scheme ◽  
Provably Secure

Electronic prescription is increasingly popular in our society, particularly in technologically advanced countries. Due to strict legal requirements and privacy regulations, authorization and data confidentiality are two important features in electronic prescription system. By combining signature and encryption functions, signcryption is an efficient cryptographic primitive that can be used to provide these two features. While signcryption is a fairly established research area, most signcryption schemes proposed recently have several limitations (e.g., high communication costs, limited bandwidth, and insecurity), and designing secure and practical signcryption schemes remains challenging. In this paper, we propose an improved certificateless proxy signcryption (CLPSC) scheme, based on elliptic curve cryptography (ECC). We also demonstrate that the proposed CLPSC scheme is secure in the random oracle model and evaluate its performance with related schemes. The security and performance evaluations show that the proposed CLPSC scheme can potentially be implemented on resource-constrained low-computing mobile devices in an electronic prescription system.

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